Abstract: A logic circuit determines the logic based only on a change in electric current. The logic circuit comprises a logical value determination circuit, a reference current generator, and a current sense amplifier. The logical value determination circuit defines a logical current flowing in response to multiple logic-signals. The reference current generator produces a reference current which is used to determine whether the logical current defined by the logical value determination circuit is true or false. The current sense amplifier detects and amplifies a difference between the logic current and the reference current.

Abstract: A CMOS OR circuit is fast and has a reduced sensitivity to the variations in the process, temperature and voltage supply. When the input signal to any one of a plurality of select transistor is in a logic high, a fixed supply of current is provided to the common drain terminal of the select transistors thereby to limit the amount of voltage swing of the common drain terminal and the common source terminal of the select transistors. A maximum power sensor senses the voltage differential developed between the common drain and the common source terminals of the select transistors and in response thereto generates a control signal which varies the amount of current that a variable current supply delivers to the common drain terminal thereby to prevent the output signal of the OR circuit from switching to the wrong state.

Abstract: The present invention relates to an inverter for high voltage full swing output, for generating an inverter output changing into full swing corresponding to a supply voltage of a high voltage circuit which is m (integer) times higher than a supply voltage of a low voltage circuit, the inverter including a switching circuit having 2 m transistors stacked one upon another, a feedback control circuit supplying gates of the 2 m transistors of the switching circuit with a bias voltage by reducing a full swing inverter output voltage, and a shield voltage source generating a shield voltage to control transmission of the bias voltage.

Abstract: An m-of-n threshold gate is disclosed having an output stated derived from the voltage of a signal node. A “Go-to-Data” circuit pulls the signal node to a first state, corresponding to an ASSERTED (logically meaningful) output when a threshold number of inputs is in the ASSERTED state. A “Go-to-NULL” circuit pulls the signal node to a second state, corresponding to a NULL (logically meaningless) output when all inputs are in the NULL state. In a semi-dynamic embodiment, a weak feedback transistor holds the signal node in a predetermined state when some, but less than the threshold number of inputs is ASSERTED. In a dynamic embodiment, the signal node becomes isolated when less than the threshold number of inputs is ASSERTED, but holds sufficient charge to maintain the signal node in a state that existed at the time of isolation. A variety of GTN circuits are disclosed.

Abstract: For the relation between the first and second pass-transistor circuits (PT1, PT2), the output signal of the preceding-stage is supplied to the gate of the succeeding-stage, and for the relation between the second and third pass-transistor circuits (PT2, PT3), the output signal of the preceding-stage is supplied to the source-drain path of the succeeding-stage. The first pass-transistor circuit (PT1) receives on its first input node (In1) and second input node (In2) the first input signal and the second input signal that are logically independent from each other. This logic circuit requires a smaller number of transistors and is capable of reducing the power consumption and delay and accomplishing an intricate logic function.

Abstract: A comparator which improves a comparing speed and has a simple logic circuit compared to the conventional adder or subtracter includes: a plurality of pre-comparing units for comparing two inputs A, B by dividing each of the inputs by 4 bits; a selection logic unit for receiving an equality signal among signals from the pre-comparing units and outputting a selection enable signal; a plurality of pass logic units enabled by the selection enable signal of the selection logic unit and outputting outputs of the pre-comparing units and the input A; and a post-comparing unit for receiving and comparing a 4-bit output of the pre-comparing units which is outputted through the enabled pass logic units and the input A.

Abstract: The present invention relates to an inverter for outputting high voltage in use of CMOS transistors of low voltage, more particularly, to a circuit generating a high voltage output without subsidiary shield voltage.

Abstract: A variable base drive output circuit that is operational for low-potential power supplies. The output circuit includes a current regulating branch and a base drive branch. A control transistor is logically coupled to an enable signal and an input signal to be propagated. Activation of that control transistor establishes a current path to the base of a bipolar pulldown transistor that is coupled to output. The current regulating branch includes a resistance device in series with current limiting transistors. The resistance device is coupled to the control node of a base current transistor such that when the load on the output node drops, the current to the base of the pulldown transistor also drops. The result is a savings in Icc current for logic LOW signals at the output node. The variable base drive output circuit is operable for low supply potentials.

Abstract: In a DCFL circuit, a high-speed operation is conducted in a stable state regardless of its load capacitance. The circuit includes a buffer circuit. Added to the buffer circuit is a pull-up circuit conducting a pull-up operation for a predetermined period of time when an output potential of the circuit changes from a low level to a high level. A first EFET of the pull-up circuit includes a gate electrode connected to an output terminal of a logic stage, a drain electrode coupled with a positive power source, and a source electrode linked with a drain of a second EFET. The second EFET includes a gate electrode connected to a node linked in series to a resistor element. The resistor is coupled with an input terminal. The second EFET includes the drain electrode connected to a source electrode of the first EFET and a source electrode linked with an output terminal.

Abstract: A method is provided for precharging a node in an integrated circuit in which the node is precharged a first predetermined delay after the node evaluates and, thereafter, the precharge ceases after a second shorter predetermined delay.

Abstract: Briefly, in accordance with one embodiment of the invention, an integrated circuit includes: two transistors coupled together in the integrated circuit so that upon the application of complementary voltage signals, electrical charge is substantially evenly distributed between output nodes. Briefly, in accordance with one more embodiment of the invention, an integrated circuit includes: a charge recycle circuit including two transistors. Briefly, in accordance with another embodiment of the invention, an integrated circuit includes: a charge recycle circuit including a first and second transistor coupled so as to respectively receive complementary voltage signals at the control voltage port of the first and second transistors. The transistors have a threshold voltage level different from the threshold voltage level of other transistors coupled to the charge recycle circuit.

Abstract: A semiconductor integrated circuit includes a power supply circuit having a global source line VCC, a local source line QVCC coupled to VCC by a source switching transistor, and a global ground line VSS, a low-threshold logic (combinational) circuit connected between QVCC and VSS, and a data storage (sequential) circuit, connected between VCC and VSS. The data storage circuit includes a low-threshold input section for receiving data from the logic circuit and a high-threshold latch section for latching the data received by the input section. Mode switching transistors are inserted between the low-threshold logic circuit and VSS, between low-threshold input section and VCC and between the low-threshold input section and VSS, for effecting a sleep mode of the semiconductor integrated circuit. Low power dissipation is maintained with a reduced circuit scale.

Abstract: A semiconductor integrated circuit is constructed with composite pass-transistor logic circuits serving as elementary circuit units each including a plurality of pass-transistor logic trees and a multiple-input logic gate. A wide variety of logical operations, even complex opearations, can be efficiently expressed using the composite pass-transistor logic circuit, and the resultant logic circuit can operate at a high speed. Thus, the semiconductor integrated circuit of the present invention can realize various logic functions required for various users in an efficient fashion. The present invention is particularly useful when applied to a field-programmable gate array integrated circuit, since complex logical operations can be expressed in a simple and efficient fashion by the composite pass-transistor logic circuits. The gate array integrated circuit obtained in accordance with the present invention can operate at a high speed with low power consumption.

Abstract: An hysteresis input buffer includes a first CMOS inverter generating a node signal, a second CMOS inverter coupled to the first CMOS inverter, inverting the node signal from the first CMOS inverter, and producing an intermediate signal, and a hysteresis control circuit coupled to the second CMOS inverter, receiving the intermediate signal, and producing an output signal having a low level during a predetermined delay time and a high level after the predetermined delay time has elapsed.

Abstract: A semiconductor integrated circuit device includes a semiconductor substrate, a MOS transistor formed on the semiconductor substrate and having a first gate, wherein a first signal supplied to the first gate and a second signal supplied to a substrate region corresponding to the semiconductor substrate are combined with each other so that one logical signal is transmitted.

Abstract: Asynchronous circuitry provides a domino circuit having short cycle times and zero overhead latency. The control circuit of a datapath circuit may utilize a completion signal from the datapath circuit to develop a request signal to the datapath circuit. The request signal may also be based on a request signal from a previous stage. Using the completion signal of a stage to develop the request signal for the same stage allows the circuitry to reduce the impact of constraints that are required for the asynchronous circuitry to operate. Similarly, using the request signal from a previous stage of the asynchronous circuitry to develop the request signal for a present stage also allows the circuitry to reduce the impact of constraints required to implement the asynchronous circuitry. These techniques allow the achievement of fast cycle times while maintaining zero overhead.

Abstract: OCD circuitry is provided for an integrated circuit having a split rail power supply providing a first and a second voltage. The OCD circuitry comprises a tristate logic circuit adapted to control the OCD and a detection circuit coupled to the tristate logic circuit and adapted to generate an inactivation signal that inactivates the OCD if the first voltage is low. The detection circuit preferably comprises a comparator that compares the first voltage to the second voltage, and that generates the inactivation signal if the first voltage is less than the second voltage. To prevent the inadvertent inactivation of the OCD circuitry, the detection circuit preferably is provided with a filter that sets a minimum time period that the first voltage must be low before the detection circuit generates the inactivation signal and thus inactivates the OCD circuitry.

Abstract: The present invention addresses the foregoing needs by providing a circuit implemented in SOI (silicon on insulator) CMOS, which includes a first node precharged to an activated level, a first transistor coupled between the first node and the second node, a second transistor coupled between the second node and a ground potential, and a third transistor coupled to the second node and operable for preventing the second node from rising to the activated level. The third transistor prevents the parasitic bipolar effect from raising this second node to the activated level. Essentially, the third transistor maintains the second node substantially at a ground level.

Abstract: A MOS logic circuit includes: a pass-transistor logic circuit, including at least one first MOS transistor, for performing a predetermined logic operation to provide an output; and an amplifying circuit, including at least one second MOS transistor, for enhancing a driving capability of the output of the pass-transistor logic circuit. Each of the first MOS transistor and the second MOS transistor is a DTMOS transistor having a gate connected to an associated well in which a channel thereof is formed.

Abstract: The present invention provides a data processing apparatus comprising a precharged circuit having at least one input line arranged to be precharged to a first logic value during a precharge phase, and a conditional-invert circuit connected to a first at least one input line and arranged to provide a first data value or the inverted first data value on the first input line during an active phase following the precharge phase.

Abstract: Circuit structure and resulting circuitry for multiple-valued logic. The circuit structure allows the design and fabrication of any r-valued logic function of n-places where r is an integer greater than 1 and n is an integer greater than 0. This structure is called SUpplementary Symmetrical LOgic Circuit structure (SUS-LOC). In circuits incorporating SUS-LOC, circuit branches are realized that uniquely deliver circuit response and output. For some circuits, and due to the operating characteristics of the switch elements, additional circuit elements, or stages, must be incorporated to prevent "back biasing." SUS-LOC is fully active. Only active elements perform logic synthesis and those components not directly related to logic synthesis, such as resistors and/or other passive loads, are relegated the task of circuit protection.

Abstract: This invention involves logic circuits formed of metal oxide semiconductor field effect transistors having differing threshold voltages. In a first embodiment, the logic circuit includes a first and a second series connection. The first series connection between a first supply voltage and an output node consists of a source-drain path of an N-channel transistor having a high threshold voltage and a pull-down conditional conduction path of a pull-down network constructed exclusively of transistors having a low threshold voltage. The second series connection between said supply voltage and said output node consists of a source-drain path of a P-channel transistor having the high threshold voltage and a pull-up conditional conduction path of a pull-up network constructed exclusively of transistors having the low threshold voltage. The two high threshold voltage MOSFETs receive at their respective gates inverse signals so that either both are conducting or both are off.

Abstract: Circuit designs of basic digital logic gates are disclosed using Resonant Tunneling Diodes (RTDs) and MOSFETs, which reduces the number of devices used for logic design, while exploiting the high speed negative differential resistance (NDR) characteristics of RTDs. Such logic circuits include NAND, NOR, AND, and OR gates and Minority/Majority circuits, which are used in full adder circuits. By implementing RTDs along with conventional MOSFETs, the use of series connected MOSFETs, which results in low output rise and fall times, especially for a large number of inputs, can be avoided. Furthermore, the RTD logic design styles do not require the use of resistors or any elaborate clocking or resetting scheme.

Abstract: The present invention comprises a logic device with improved capacitance isolation and a design methodology for reducing unwanted parasitic capacitance in logic circuits. The logic device further comprises an output signal having a first internal evaluate node and a second evaluate node. Additionally, the logic device comprises a first input signal that has a first input wire and a second input wire where the first input wire corresponds to a first possible value of the first input signal and the second input wire corresponds to a second possible value of the first input signal. The logic device further comprises a first plurality of intermediate nodes that includes a first intermediate node. Additionally, the logic device includes a first plurality of transistors that further includes a first transistor coupling the first internal evaluate node to the first intermediate node and being gated by the first wire of the first input signal.

Abstract: A clock buffer includes a clocked pull-up transistor and a clocked pull-down transistor. The clocked pull-up transistor has a drain coupled to an output line and a gate coupled to a clock signal line. The clocked pull-down transistor includes a drain coupled to the output line, a gate coupled to the clock signal line, and having a width Y. The buffer further includes a first pull-down transistor having a drain coupled to a source of the clocked pull-down transistor, a gate coupled to a first input signal line, and having a width that is at least 10% greater than Y. This clock buffer provides reduced power consumption in comparison to a more conventional clock buffer.

Abstract: Disclosed is an energy economized pass-transistor logic having a level restoration circuit (50) free from leakage and a full adder using the same. The logic comprises a functional block (10) having a plurality of n type FETs (M1 . . . M4), for performing at least one logical function of inputs (12, 14, 16, 18) to generate two complementary signals (20, 22), the complementary signals (20, 22) being a weak high level signal and a strong low level signal; and a level restoration block (50) having first and second CMOS inverters (52, 54), for restoring the weak high level signal to a strong or full high level signal and preventing a leakage current flowing through one of the first and the second CMOS inverters (52, 54) where the weak high level is applied.

Abstract: A semiconductor circuit includes an input, an output, and a first transistor and a second transistor coupled in series to a power source. The first transistor is coupled closer to the power source than the second transistor is, and the first transistor has a higher threshold voltage than a threshold voltage of the second transistor. The semiconductor circuit further includes a capacitor which is coupled between the first transistor and the second transistor.

Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.

Abstract: A current mode logic circuit has a first and second NMOS transistors N1 and N2, an input terminal IN connected to both gates of the first and second NMOS transistors N1 and N2 to input data, a reference voltage input terminal REF, an output terminal OUT connected to a drain of the first NMOS transistor N1, and a current power source I connected both sources of the first and second NMOS transistors N1 and N2. Body terminals of the first and second NMOS transistors N1 and N2 are connected to the input terminal IN and the reference terminal REF, respectively so that the body voltage of each of the first and second NMOS transistors N1 and N2 is controlled.

Abstract: Briefly, in accordance with one embodiment of the invention, an integrated circuit includes: two transistors coupled together in the integrated circuit so that upon the application of complementary voltage signals, electrical charge is substantially evenly distributed between output nodes. Briefly, in accordance with one more embodiment of the invention, an integrated circuit includes: a charge recycle circuit including two transistors. Briefly, in accordance with another embodiment of the invention, an integrated circuit includes: a charge recycle circuit including a first and second transistor coupled so as to respectively receive complementary voltage signals at the control voltage port of the first and second transistors. The transistors have a threshold voltage level different from the threshold voltage level of other transistors coupled to the charge recycle circuit.

Abstract: A NOR gate including a pull-down circuit coupled to a pull-up circuit. The NOR gate is configured to drive an output signal to a low logic state at a substantially uniform slew rate regardless of the number of input signals that are in high logic state. The pull-down circuit may include a first plurality of transistor circuits each coupled to a corresponding one of the plurality of input signals, and a second plurality of transistor circuits each comprising a plurality of transistors coupled in parallel with each other and coupled to a corresponding one of the plurality of input signals or a complement of a corresponding one of the plurality of input signals. The first and second plurality of transistor circuits may each include an n-channel MOS (NMOS) transistor. The NOR gate may be incorporated into a decoder of a synchronous or asynchronous input path circuit to generally reduce the set-up and hold time window of the input path circuit.

Abstract: In brief, methods and apparatus are provided for bipolar elimination in silicon-on-insulator (SOI) domino circuits. Apparatus for bipolar elimination in silcon-on-insulator (SOI) domino circuit includes a domino silicon-on-insulator (SOI) field effect transistor. An input is coupled to the domino silicon-n-insulator (SOI) field effect transistor. A predischarging device is coupled to said domino silicon-on-insulator (SOI) field effect transistor. The predischarging device is activated during a precharge mode of the domino circuit, so that the SOI parasitic bipolar transistor is not activated. A dynamic input circuit couples the input to the domino silicon-on-insulator (SOI) field effect transistor. The output of the dynamic input circuit is low during the precharge mode. The output of the dynamic input circuit corresponds to the input during the evaluate mode. The output of the dynamic input circuit is used to gate the predischarging device.

Abstract: A common mode logic (CML) circuit having an improved bias circuit and an active MOS load operating exclusively in the triode region to provide improved performance characteristics including a high speed of operation. The bias circuit of the CML circuit comprises a pair of MOS transistors, one of which has an aspect ratio (W.sub.P /L.sub.P) and the other of which has an aspect ratio (W.sub.P /L.sub.P)/n, wherein 1<n<4. This configuration causes a third MOS transistor in the bias circuit to operate exclusively in the triode region. The CML circuit also includes a logic portion, which may be a logic gate or flip-flop, having a plurality of pairs of input MOS transistors for receiving differential input signals. In accordance with the invention, the logic portion has load MOS transistors which operate exclusively in the triode region.

Abstract: A circuit and a method are disclosed for a Schmitt trigger stage which converts transistor-transistor logic (TTL) into metal oxide semiconductor (MOS) logic signal levels using all MOS devices. The circuit reduces the standby current of the n-channel transistor of the input section of the Schmitt trigger stage by adding a MOS diode to the bottom the input section. When higher than normal supply voltages are used, the standby current of the p-channel transistor of the input section can be reduced by adding a MOS diode to the top of the input section. In addition, a small MOS transistor, connected across the output Schmitt trigger inverter, eliminates leakage currents in that inverter.

Abstract: A CMOS logic circuit comprises a logic gate having an input node (e.g., a storage node) coupled to a positive supply potential through a p-type field-effect transistor (PFET), with one or more n-type field-effect transistors (NFETs) being coupled between the storage node and a negative supply potential. Since the response of the circuit to a high-energy particle strike is dominated by the N+ diffusion associated with the NFETs when the state of the storage node is high, i.e., a logical "1", the gate has a switching point that is set closer to the negative supply potential than to the positive supply potential.

Abstract: According to the preferred embodiment, a device and method for reducing power consumption by reducing unneeded node toggling is provided. The preferred embodiment reduces unneeded node toggling in a circuit by utilizing either a pull-up or pull-down transistor to pull the input of the circuit to a state that minimizes power consumption during periods in which the circuit is inactive. By tying the circuit input high or low during inactivity, node toggling is reduced or eliminated in that circuit. In the preferred embodiment, the inputs to the circuit all pulled after a time of inactivity which is proportional to the leakage current of the leakiest transistor in the circuit. By timing the input pulling proportional to the leakage current, the power consumption is minimized without excessive power loss caused by the pulling itself.

Abstract: Logic books with mixed low V.sub.t and regular V.sub.t devices provide a performance gain without the large increase in stand-by power of the logic book. Low V.sub.t devices are used to gain speed, and regular V.sub.t devices are used to cut off the off-current of the logic book. The optimization of mixed V.sub.t configurations is important. No single path between an output and ground can be made of all low V.sub.t devices, and no single path between the output and V.sub.dd can be made of all low V.sub.t devices. Generally, devices that are connected to V.sub.dd and ground should be regular V.sub.t devices, a low V.sub.t devices should be connected closest to the output. All low V.sub.t devices should be appropriately reversely biased in their off states. Because its merits in standby power, speed and noise margin, such mixed-low-and-regular-V.sub.t logic books can have a wide use in VLSI designs (e.g., high performance microprocessor design).

Abstract: The threshold value logic has a non-inverting circuit path (S) that and an inverting circuit path (S') are connected to at least one comparative weighting subcircuit (BC, BS). The non-inverting circuit path and the inverting circuit path preferably are of identical construction and each contain at least one neuron transistor (NT1, NT1'). The corresponding neuron transistor gates in the non-inverting circuit path and in the inverting circuit path are driven inversely with respect to one another.

Abstract: A logic circuit for use as a selector having multiple inputs and high operation speed. The logic circuit includes a first FET having a first electrode connected to a first power supply, a second electrode connected to an output terminal and a third electrode connected to an intermediate control node, and a plurality of logic blocks parallelly connected between the second power supply and the output terminal. Each logic block includes second and third FETs being of a conductivity type opposite to that of the first FET and connected in series between the output terminal and a second power supply. Each logic block also includes a fourth FET being of the same conductivity type as the second and third FETs and having a third electrode connected to the third electrode of the second FET, a first electrode connected to the third electrode of the third FET and a second electrode connected to the intermediate control node.

Abstract: In the circuit arrangement two of the four vertical transistors are complementary to the remaining two transistors. Two of the transistors are respectively arranged at the same level. For this purpose, layer structures (St1, St2, St3, St4) are structured that respectively have at least a channel layer and a source/drain region of one of the transistors. All the layer structures (St1, St2, St3, St4) can be produced from a layer sequence with only four layers. In order to avoid leakage currents due to a parasitic bipolar transistor, the layer structures (St1, St2, St3, St4) can be realized very thinly, using spacer-type masks. Electrical connections between parts of the four transistors can take place via layers of the layer sequence. The contacting to the output voltage terminal can take place via a step that is formed by two layers of the layer sequence.

Abstract: A high-speed dynamic logic circuit having a high tolerance to noise includes pMOS and nMOS transistors constructing a buffer, which is connected to an internal dynamic node, for driving an output terminal. Only the pMOS transistor, which operates in an evaluation cycle, is connected to the dynamic node. The nMOS transistor is driven by a signal that is the inverse of a precharge signal. A weak latch, or an nMOS transistor of minimum size driven by the dynamic node, is connected to the output terminal as a leakage compensation circuit.

Abstract: A variable voltage driver circuit produces an output swing off of a single voltage power supply which is logically configurable to allow interconnection of CMOS chips of varying technologies and power supplies. First a voltage requirement for a destination chip is identified to which a driver chip is to be coupled, and the voltage requirement for the driver chip is identified. The variable voltage driver circuit is activated to produce a variable voltage output swing off of a single voltage power supply meeting the voltage requirements of the driver chip. The driver has data input, and level selection inputs and pins which select and enable the driver independent of the output level state that the driver is in.

Abstract: A CMOS driver circuit minimizes a pass-through current flowing from a first voltage terminal to a second voltage terminal during transitions of an input signal. At least two transistors are connected in series between two voltage terminals. One transistor turns off when the input signal transitions from a low logic state to a high logic state. Another transistor turns off when the input signal transitions high-to-low. During either input signal transition, one of the transistors is off, thereby cutting the path between the voltage terminals to reduce or eliminate the pass-through current. The two transistors are controlled by the output of the circuit through a feedback loop. This feedback loop can include a delay element, one transistor controlled by a single synchronizing clock signal, or two transistors controlled by two complementary clock signals. The driver circuit can be used as a building block to provide conventional combination logic functions.

Abstract: A regenerative amplifier is coupled to a combinational current-steering network to provide a combinational logic and register combination. A differential change in current on the register's input nodes due to current steering is amplified to provide complementary logic values at the output nodes of the register responsive to a clock signal. Various combinational logic functions are implemented by current steering networks. Such a configuration provides the advantages of economy of size, cost and power consumption in the combinational layout because the current steering transistors may be made smaller. Furthermore, such a configuration provides the advantage of decreased set-up time in a registered data path and immunity from external sources of noise via common mode rejection. In one embodiment, a regenerative amplifier includes cross-coupled inverters.

Abstract: A differential current switch logic (DCSL) system is provided which has an evaluation tree including a plurality of input terminals and a pair of complementary output nodes. The DCSL system also has an output network which establishes a pair of state outputs at a predetermined level during a precharge phase and establishes the state outputs at complementary levels in response to the evaluation tree output nodes during an evaluate phase. First and second NMOS transistors are connected in series between the DCVS output state network and the evaluation tree output nodes with their gates coupled to the state outputs to isolate the outputs from the evaluation tree following evaluation.

Abstract: An input/output (I/O) buffer is provided for use in an integrated circuit, which is designed in particular to be capable of accepting an input logic signal voltage higher in voltage level than the system voltage. The I/O buffer is designed in such a manner that when the input logic signal drops from the high-voltage logic state to the low-voltage logic state, the voltage at the floating N-well can be raised to near the level of the system voltage. This prevents a latchup effect that occurs in the prior art. Moreover, the I/O buffer can prevent both the output PMOS transistor and the output NMOS transistor from switching into a conducting state at the same time. This prevents the occurrence of an instant short-circuit current in the I/O buffer and also helps to improve the output performance of the I/O buffer.

Abstract: A method and apparatus for reducing power consumption in a domino logic is provided. An input of the domino logic block has as an output of an upstream logic block. A first state, e.g. default or idle, of the output of the upstream logic block is determined. The an output of the domino logic block corresponding to the said first state is determined. A logic block is modified, such that the output of the domino logic block for the first state is the same as a precharge state of the output. This results in preventing the output of the domino logic block from toggling when the first state is the input to the domino logic block.

Abstract: A circuit structure which avoids a latchup effect. An N-well is formed in a P-type substrate. An N-type contact is formed in the N-well. A PMOS is located on the N-well. A gate of the PMOS connects to an input terminal and a source region of the PMOS connects to a voltage source. A first NMOS and a second NMOS are located on the P-type substrate. A gate of the first NMOS connects to the input terminal, a source region of the first NMOS connects to a ground terminal, and a drain region of the first NMOS connects to an output terminal and a drain region of the PMOS. A gate of the second NMOS connects to the output terminal, a source region of the second NMOS connects to a voltage source, and a drain region of the second NMOS connects to the N-type contact.

Abstract: A zero power AND or NOR (AND/NOR) gate includes circuitry configured for use in a field programmable gate array (FPGA). The AND/NOR gate includes multiple driver circuits each receiving a single input of the AND/NOR gate, each driver circuit being connected by a NORCNTL line and a NOROUT line to a current switch circuit. The NOROUT line provides the output of the AND/NOR gate, while the NORCNTL line enables zero power operation. The driver circuits can be included in input/output buffers (IOBs), configurable logic blocks (CLBs), or other components throughout an FPGA to receive more inputs than typically provided to a single CLB. Each of the driver circuits includes a pull down transistor having a gate receiving an input signal (IN.sub.1 -IN.sub.N) of the AND/NOR gate, and having a source to drain path connecting the NOROUT line to Vss.

Abstract: An N-input transistor logic circuit includes two or four series-connected transistor arrays connected between two power lines. The gates of the transistors are connected to the N inputs to account for varying parasitic input capacitances, and equalizes the resulting time delays between the N-inputs and the logical unit output. Specifically, in each of the arrays each of the transistors is connected to one of the N inputs, and is separated from a first power line by X other transistors in the respective array. For each of the input terminals, the sum of X for all the arrays is a constant, namely, 2N-2 for four arrays and N-1 for two arrays.