Abstract: A lookup table with low power consumption is provided. The lookup table includes a memory element including a transistor and a capacitor. A drain of the transistor is connected to one electrode of a capacitor and the input of an inverter, and a source is connected to a first wiring. The other electrode of the capacitor is connected to a second wiring. In such a memory element, the potential of the second wiring is complementary to the potential of the first wiring when writing data; accordingly, the potential of the drain of the transistor, i.e., the potential of the input of the inverter can be higher than the high potential of the inverter. Thus, shoot-through current of the inverter at this time can be significantly reduced. As a result, power consumption in a standby state can be significantly reduced.

Abstract: An electronic device includes a pulsed latch circuit configured to latch a data input signal to an output based upon receipt of a pulse signal. A pulse generation circuit is configured to compare the data input signal and an output signal at the output of the pulsed latch circuit, and to generate the pulse signal based upon a mismatch therebetween in response to a clock signal.

Abstract: A semiconductor storage device which stops and resumes the supply of power supply voltage without the necessity of saving and returning a data signal between a volatile storage device and a nonvolatile storage device is provided. In the nonvolatile semiconductor storage device, the volatile storage device and the nonvolatile storage device are provided without separation. Specifically, in the semiconductor storage device, data is held in a data holding portion connected to a transistor including a semiconductor layer containing an oxide semiconductor and a capacitor. The potential of the data held in the data holding portion is controlled by a data potential holding circuit and a data potential control circuit. The data potential holding circuit can output data without leaking electric charge, and the data potential control circuit can control the potential of the data held in the data holding portion without leaking electric charge by capacitive coupling through the capacitor.

Abstract: According to one embodiment, a semiconductor integrated circuit includes a clock signal transmission path configured to transmit a clock signal and a data transmission path configured to transmit data. The clock signal transmission path has a first and a second clock signal transmission line configured to transmit a clock signal and a complementary clock signal. The data transmission path has a first and a second data transmission line configured to transmit data and complementary data. Each transmission path has an amplifier circuit of each signal and a level adjustment circuit for reducing amplitude of output from the amplifier circuit.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

Abstract: One embodiment of the present invention sets forth a technique for capturing and storing a level of an input signal using a single-trigger low-energy flip-flop circuit that is fully-static and insensitive to fabrication process variations, The single-trigger low-energy flip-flop circuit presents only three transistor gate loads to the clock signal and none of the internal nodes toggle when the input signal remains constant, The output signal Q is set or reset at the rising clock edge using a single- trigger sub-circuit. A set or reset may be armed while the clock signal is low, and the set or reset is triggered at the rising edge of the clock.

Abstract: An object is to provide a semiconductor device which can suppress characteristic deterioration in each transistor without destabilizing operation. In a non-selection period, a transistor is turned on at regular intervals, so that a power supply potential is supplied to an output terminal of a shift register circuit. A power supply potential is supplied to the output terminal of the shift register circuit through the transistor. Since the transistor is not always on in a non-selection period, a shift of the threshold voltage of the transistor is suppressed. In addition, a power supply potential is supplied to the output terminal of the shift register circuit through the transistor at regular intervals. Therefore, the shift register circuit can suppress noise which is generated in the output terminal.

Abstract: An integrated circuit device comprises a first clock signal source, arranged to provide at least one first clock signal; a second clock signal source, arranged to provide at least one second clock signal different from the at least one first clock signal; and a plurality of sequential logic cells, at least one of the plurality connected to receive, in a first mode, the at least one first clock signal or at least one clock signal derived from the at least one first clock signal, and to receive, in a second mode, the at least one second clock signal or at least one clock signal derived from the at least one second clock signal; wherein in the second mode the at least one second clock signal is adapted to the at least one of the plurality of sequential logic cells to generate in at least a portion of the integrated circuit device a current consumption when the at least one first clock signal is not a toggling signal.

Abstract: One embodiment of the present invention sets forth a technique for capturing and holding a level of an input signal using a latch circuit that presents a low number of loads to the clock signal. The clock is only coupled to a bridging transistor and a pair of clock-activated pull-down or pull-up transistors. The level of the input signal is propagated to the output signal when the storage sub-circuit is not enabled. The storage sub-circuit is enabled by the bridging transistor and a propagation sub-circuit is activated and deactivated by the pair of clock-activated transistors.

Abstract: Sense amplifier-type latch circuits are provided which employ static bias currents for enhancing operating frequency. For example, a sense amplifier-type latch circuit includes a latch circuit that captures and stores data during an evaluation phase of the sense amplifier-type latch circuit, and outputs the stored data to differential output nodes. An input differential transistor pair has drains connected to the latch circuit and sources commonly connected to a coupled source node. A static bias current circuit is connected to the coupled source node to provide a static bias current which flows through the differential transistor pair and cross-coupled inverters of the latch during a precharge phase. A switch device, which is connected to the coupled source node, is turned off during the precharge phase and turned on during the evaluation phase by operation of a clock signal to increase current flow through the differential transistor pair.

Abstract: An object is to provide a semiconductor device which can suppress characteristic deterioration in each transistor without destabilizing operation. In a non-selection period, a transistor is turned on at regular intervals, so that a power supply potential is supplied to an output terminal of a shift register circuit. A power supply potential is supplied to the output terminal of the shift register circuit through the transistor. Since the transistor is not always on in a non-selection period, a shift of the threshold voltage of the transistor is suppressed. In addition, a power supply potential is supplied to the output terminal of the shift register circuit through the transistor at regular intervals. Therefore, the shift register circuit can suppress noise which is generated in the output terminal.

Abstract: A multistage latch-based isolation cell is provided. The isolation cell includes a latch to receive a first binary signal and an enable signal. The latch initially supplies a second binary signal with an unknown value in response to the enable port receiving an enable signal having a first polarity value, and subsequent to receiving the first binary signal with a first value, supplying the second binary signal with the first value. The isolation cell includes a delay device to receive the enable signal and to supply a delayed enable signal. A reset latch receives the second binary signal, the delayed enable signal, and a reset pulse. The reset latch supplies a third binary signal equal to the first value in response to the reset latch receiving the reset pulse, followed by the delayed enable signal with the first polarity value, followed by the second binary signal.

Abstract: Disclosed herein are a delay latch circuit and a delay flip-flop circuit arranged to inhibit the increase in power consumption while preventing malfunction under low voltage conditions. An internal signal output circuit outputs as an internal signal an inverted signal of a data signal starting from an internal transparency start timing until an internal transparency end timing. From the internal transparency end timing until the internal transparency start timing, the internal signal output circuit outputs a fixed value signal as the internal signal. A transistor delays the output internal signal over a time period which ranges from a hold instruction delay timing to the issuance of a data transparency instruction and which includes the internal transparency end timing therebetween.

Abstract: Integrated circuits with communications circuitry are provided. The communications circuitry may include at least first and second flip-flops connected in a chain along a data path. The first flip-flop may be controlled by a clock signal. The clock signal may be fed to a delay matching circuit. The delay matching circuit may provide a delayed version of the clock signal that controls the second flip-flop. The delay provided by the delay matching circuit may be equal to a clock-to-output delay of the first flip-flop. The delay matching circuit may have the same physical arrangement as the first flip-flop. The first and second flip-flops and the delay matching circuit may include dynamic sense amplifier flip-flops. The delay matching circuit may have an input that receives a high signal, a control input that receives the clock signal, and an output over which the delayed clock signal is provided.

Abstract: A low-hysteresis high-speed latch circuit is disclosed which isolates a sample stage and hold stage from one another during a latch clock phase and simultaneously shorts the output nodes together during the latch clock phase to reduce hysteresis of the latch.

Abstract: One embodiment of the present invention sets forth a technique for capturing and storing a level of an input signal using a single-trigger low-energy flip-flop circuit that is fully-static and insensitive to fabrication process variations. The single-trigger low-energy flip-flop circuit presents only three transistor gate loads to the clock signal and none of the internal nodes toggle when the input signal remains constant. The output signal Q is set or reset at the rising clock edge using a single-trigger sub-circuit. A set or reset may be armed while the clock signal is low, and the set or reset is triggered at the rising edge of the clock.

Abstract: A synchronizer constituted of a first and second set of three serially coupled latches coupled to a common clocking signal, the first and the ultimate latch of the first set responsive to a first edge of a common clocking signal and the penultimate latch responsive to an opposing edge of the common clocking signal, the second set being respectively responsive to the respective complementary edges of the clocking signal; an input lead arranged to receive a signal to be synchronized, the input lead coupled to the input of the first latch of the first set and to the input of the first latch of the second set; and a filter arranged to pass the output of each of the first set and the second set responsive to the penultimate latch of the set exhibiting a consistent output for two consecutive opposing edges.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

Abstract: A directional coupler with a high coupling per unit area and small variations in characteristic at manufacturing capable of achieving a high directivity easily and an RF circuit module provided with the directional coupler are achieved. A main-line is provided on a front surface of a multi-layer substrate, a ground plane is provided on a back surface of the multi-layer substrate. On an inner layer immediately under the main-line, two lines in parallel with the main-line are provided, and one line is provided on a layer closer to the ground plane than the two lines. By connecting the two lines and the one line with vias, a sub-line with a shape of a winding of a loop is formed. In the sub-line, a main component of a vector vertically penetrating the loop is horizontal with respect to the ground plane.

Abstract: Various methods and apparatus can be used for amplifying a time interval in a variety of applications. In an embodiment, a feedback device is implemented in a time amplifier in conjunction with an output device of the time amplifier.

Abstract: A flip-flop, and a frequency divider and an RF circuit using the flip-flop. The frequency divider, which receives a first signal and generates a second signal by dividing a frequency of the first signal, including a plurality of flip-flops that each latch and output a signal based on the first signal; and at least one switch unit that is switched in response to a control signal to modify a signal transfer path between the plurality of the flip-flops, wherein a different number of flip-flops are activated in response to each first and second status of the control signal so that the frequency of the first signal is divided by different multiples.

Abstract: A latched comparator circuit. The latched comparator circuit comprises a first and a second output terminal for outputting a first and a second output voltage, respectively, of the latched comparator circuit. Furthermore, the latched comparator circuit comprises a cross-coupled pair of transistors operatively connected between the first and the second output terminal for providing a positive feedback in the latched comparator circuit. In addition, the latched comparator circuit comprises a reset terminal for receiving a reset signal and reset circuitry arranged to balance the first and the second output voltage during a first phase of the reset signal and allow a voltage difference to develop between the first and the second output voltage during a second phase of the reset signal.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

Abstract: A flip-flop circuit is provided with an improved robustness to radiation induced soft errors. The flip-flop cell comprises the following elements. A transfer unit for receiving at least one data signal and at least one clock signal, a storage unit coupled to the transfer unit and a buffer unit coupled to the storage unit. The transfer unit includes a plurality of input nodes adapted to receive said at least one data signal and said at least one clock signal; a first output node for providing a sampled data signal in response to said at least one clock signal and said at least one data signal; and a second output node for providing a sampled inverse data signal, the sampled inverse data signal provided in response to said at least one clock signal and said at least one data signal. The storage unit comprises a first and a second storage nodes configured to receive and store the sampled data signal and the sampled inverse data signal.

Abstract: A dynamic floating input D flip-flop (DFIDFF) is provided. The DFIDFF includes a floating input stage, a first string of transistors, and a second string of transistors. At a pre-charge period, the floating input stage transmits the input data to the first string of transistors; the first string of transistors stores the logic status of the input data, and pre-charges its output node to a first level. At an evaluation period, the first string of transistors decides its output node level in accordance with data logic status stored in the first string of transistors; and the second string of transistors decides output level of the D flip-flop in accordance with logic status of the output node of the first string of transistors.

Abstract: A data holding circuit is capable of latching an input signal at both a rising edge and a falling edge of a clock signal. Several flip-flops and exclusive OR circuits cooperate to achieve this function.

Abstract: A flip-flop is disclosed which includes: a clock supply circuit configured to output or fix a clock signal alternating between two predetermined states in accordance with a sleep signal; a first holding circuit configured to fetch or hold an input signal in accordance with a state the clock signal indicates; a second holding circuit configured to fetch or hold a first signal output by the first holding circuit in accordance with a state the clock signal indicates; an input switching circuit configured to supply as the input signal a second signal output by the second holding circuit or to supply an external signal as the input signal in accordance with the hold signal; and a power supply control circuit configured to supply or not to supply power to the first holding circuit and the input switching circuit in accordance with a power supply control signal.

Abstract: A flip-flop circuit that captures an input signal in sync with a clock, has a first gate outputting a first signal corresponding with input signal; a second gate generating a second signal of a first predetermined level in response to a first level of clock and causing the second signal to be a level of first signal in response to a second level of clock; and a third gate outputting a third signal of second signal in response to the second level of clock. Further the flip-flop circuit has a first inversion feedback circuit between the third and second signal terminals, that is activated in response to the second level of clock and latches the third signal together with third gate; and level fixing circuit that fixes the first signal terminal at a second predetermined level with a time delay after the clock changes to the second level.

Abstract: A flip-flop includes a first circuit receiving a clock signal and the first signal and transitioning the first and second output signals to a first level when the clock signal goes to an active level, and a second circuit transitioning the first signal to the first level after the first and second output signals go to the first level. The first circuit transfers first and second input signals to the first and second output terminals from first and second input terminals when the clock signal is at the active level and the first signal is at the first level.

Abstract: A bus holder includes a first inverter, a second inverter and a pass switch. The first inverter is coupled between a first power supply voltage node and a second power supply voltage node, and receives an input signal via an input terminal to output a first output signal having an inverted phase with respect to the input signal. The second inverter is coupled between the first power supply voltage node and the second power supply voltage node, and inverts the first output signal to output a second output signal, having an inverted phase with respect to the first output signal, to an output terminal. The pass switch is coupled between the input terminal and the output terminal, and outputs a signal having a level of a control voltage to the input terminal, in response to the control voltage. Accordingly, a tolerant input/output buffer may stably maintain an input signal level when a bus is floated.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

Abstract: In the present invention, a logic circuit is provided therein with a current supply control circuit for controlling the amount of current supplied to a differential circuit. This current supply control circuit comprises a bypass path for bypassing the current around the differential circuit, a switching transistor interposed in the bypass path for opening/closing the bypass path in accordance with the signal level of a clock signal applied thereto from the outside, and a current amount control transistor for controlling the amount of current supplied to the differential circuit. The current amount control transistor adjusts the amount of current in accordance with the signal level of the clock signal.

Abstract: Power consumption may be reduced through the use of power gating in which power is removed from circuit blocks or portions of circuit blocks in order to reduce leakage current. One embodiment uses a modified state retention flip-flop capable of retaining state when power is removed or partially removed from the circuit. Another embodiment uses a modified state retention buffer capable of retaining state when power is removed or partially removed from the circuit. The state retention flip-flop and buffer may be used to allow for state retention while still reducing leakage current. Also disclosed are various methods of reducing power and retaining state using, for example, the state retention flip-flops and buffers. For example, software, hardware, or a combination of software and hardware methods may be used to enter a deep sleep or idle mode while retaining state.

Abstract: A configurable latch is implemented using a configurable pulse generator and a level sensitive (LS) latch. The configurable pulse generator produces either a pulse signal that is aligned with the input clock edge, or simply provides the input clock signal to its output in response to a pulse generator control signal. If a pulse signal is provided to the latch, then edge triggered (ET) latch operation is effected within the latch. If, on the other hand, a clock signal is provided to the latch, then LS latch operation is effected within the latch. Thus, configuration of latch operation is established in response to the type of clock signal that is provided to the latch.

Abstract: An address latch circuit of a memory device is disclosed. A latch operation is disabled while an address signal makes a level transition in the memory device, and then enabled when the address signal is stabilized after the level transition. Therefore, it is possible to reduce power consumption caused during the level transition of the address signal.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems. The C3MOS structure enables the use of a power supply voltage that may be larger than the voltage required by the CMOS fabrication process, further enhancing the performance of the circuit.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems. The C3MOS structure enables the use of a power supply voltage that may be larger than the voltage required by the CMOS fabrication process, further enhancing the performance of the circuit.

Abstract: Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C3MOS logic with low power conventional CMOS logic. The combined C3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems. The C3MOS structure enables the use of a power supply voltage that may be larger than the voltage required by the CMOS fabrication process, further enhancing the performance of the circuit.

Abstract: In a first aspect, a cross-coupled inverter is provided that includes a first inverter circuit having a first NFET coupled to a first PFET and a second inverter circuit having a second NFET coupled to a second PFET. The second inverter circuit is cross-coupled with the first inverter circuit at a plurality of nodes. The body of at least one of the first NFET, the second NFET, the first PFET and the second PFET is coupled so as to form a feedback path that reduces discharging at one or more of the plurality of nodes in response to a soft error event at the cross-coupled inverter.

Abstract: A high-speed, current-driven latch is provided. The latch conducts a current and includes an output, a SET circuit and a RESET circuit. The output is variable between a first state and a second state. The SET circuit conducts the current present in the latch at the first state such that the SET circuit is maintained close to a level required to change the output of the transistor from the first to the second level, and the RESET circuit conducts the current at the second level such that the RESET circuit is close to a level required to change the output of the transistor from the second level to the first level.

Abstract: The data latch circuit of the invention includes a means for short-circuiting an input terminal and an output terminal of an inverter and by connecting the input terminal to one electrode of a capacitor and sampling a data signal or a reference potential to the other electrode of the capacitor, an accurate operation can be obtained without being influenced by variations in the TFT characteristics even when the amplitude of an input signal is small relatively to the width of a power supply voltage.

Abstract: Non-volatile latch circuit 10 of the present invention comprises ferroelectric capacitor 1 provided with a first electrode 1a, second electrode 1b, and ferroelectric film 1c that lies between these electrodes; reset terminal Tre that is connected to first electrode 1a and a CMOS inverter element 2 that is connected to second electrode 1b of ferroelectric capacitor 1; voltage switching terminal Tpl that applies a voltage to second electrode 1b; switching element 5 that is connected between second electrode 1b and second input terminal Tpl and switches a voltage applied to second electrode 1b; and set terminal Tse that applies a voltage for switching on or off switching element 5, wherein the voltage generated in second electrode 1b caused by polarization retained by ferroelectric film 1c is higher than the threshold voltage Vtn of NMISFET 4 of CMOS inverter element 2.

Abstract: Clocked full-rail differential logic circuits are provided with shut-off devices. The addition of the shut-off device provides a full-rail differential logic circuit with shut-off that does not experience the large pre-charge high or “dip” experienced by prior art full-rail differential logic circuits and is therefore more power efficient. In addition, the present invention provides a full-rail differential logic circuit with shut-off that is more resistant to noise than prior art full-rail differential logic circuits.

Abstract: For use in a strobed comparator circuit of the type comprising a decision circuit and a set-reset (SR) latch for holding an output of the decision circuit, an apparatus and method is disclosed for reducing output delay between two complementary output signals of the SR latch. During the reset phase of the SR latch, only one input to the SR latch changes state while the other input to the SR latch returns to its previous logic state. Information relating to the change of logic states of the decision circuit and of the SR latch is provided to two feed forward transistors that send the information directly to the SR latch output that is likely to have an output signal delay. The apparatus and method of the present invention causes the output signals of the SR latch to arrive at their respective output terminals at approximately the same time.

Abstract: In a latch circuit having a bistable pair of cross connected transistors of a first polarity and a third transistor of a second polarity, a current signal greater than a bias current is received at a latch circuit port, amplified with the third transistor, and applied to the latch circuit port. This decreases the time in which the latch circuit port receiving the current signal greater than the bias current reaches a steady state voltage.

Abstract: A semiconductor integrated circuit device for minimizing clock skew over clock wiring shortened for reduced wiring delays. A plurality of stages of clock drivers are provided on clock wiring paths ranging from a clock generator to flip-flops. Clock lines connecting upper stage clock drivers are equalized in length in the form of a tree structure, and clock lines connecting lower stage clock drivers are made as short as possible.

Abstract: A differential latch includes a sample transistor section, a hold transistor section, a 1st gating circuit and a 2nd gating circuit. The sample transistor section is operably coupled to sample, when coupled to a supply voltage (e.g., VDD and VSS) a differential input signal. The hold transistor section is operably coupled to latch, when coupled to the supply voltage, the sampled differential input to produce a latched differential signal. The 1st gating circuit is operable to couple the sampled transistor section to the supply voltage in accordance with a 1st clocking logic operation and a 2nd clocking logic operation. The 2nd gating circuit is operable to couple the hold transistor section to the supply voltage in accordance with a 3rd clocking logic operation and a 4th clocking logic operation.

Abstract: A scannable asynchronous preset and/or clear flip-flop having latch circuits 27 and 30. Latch circuit 27 comprises an inverter 28 and a tristate NAND gate 29. Latch circuit 30 comprises an inverter 31 and a tristate NOR gate 32. When the CLK (clock input signal) and CLRZ (the inverse of the clear input signal) are both low, the output of the tristate NOR gate 32 is forced low. Thus the input of inverter 31 is low so that the output signal, Q, is forced low and the inverse output signal, QZ, is forced high. When CLK is high and CLRZ is low the output of tristate NAND gate 29 is forced high so that the input to inverter 28 is high and the input to inverter 31 is low, thereby forcing Q low and QZ high. Thus the outputs Q and QZ are forced low and high respectively when CLRZ is low, regardless of the state of the CLK input.