Abstract: Disclosed are methods and systems for implementing various circuitry within a high speed, high frequency signal environment such as an integrated circuit. In one embodiment, an improved clock tree mechanism utilizes multiple low power drivers to distribute a clock signal to various load cells. In another embodiment, a single circuitry in current mode logic is used to implement a combined multiplexer, buffer and level shifter. In other embodiments, improved static and partially static flip-flop circuitry is disclosed which uses fewer devices and less power than conventional circuitry while achieving the same functionality.

Abstract: A multi-threshold flip-flop includes a master latch, a slave latch, and at least one control switch. The master latch is composed of an input buffer formed with low threshold (LVT) transistors and a first latch circuit formed with LVT transistors. The slave latch is composed of a second latch circuit formed with high threshold (HVT) transistors and an output driver formed with LVT transistors. The at least one control switch enables or disables the LVT transistors and is implemented with at least one HVT transistor. The LVT and HVT transistors may be N-FETs and/or P-FETs. The multi-threshold flip-flop can operate at high speed, has low leakage current, and can save the logic state when disabled.

Abstract: A static frequency divider circuit includes a first and second latch that are interconnected by a series path circuit and by a feedback path circuit. Each of the latches includes a reading BALLSACKbranch and a latching branch. The series path circuit includes a push-pull current driver to speed state transitions between the latching branch of the first latch and the reading branch of the second latch. Similarly, feedback path circuit includes a push-pull current driver to speed state transitions between the latching branch of the second latch and the reading branch of the first latch.

Abstract: A clocked scan flip-flop 2 is provided in which a latch 14 within the diagnostic data path is reused to store an operational signal value during a sleep mode. The operational signal value is supplied to the latch 14 via a sleep mode path 20 through a transmission gate 22 (or other tristate driver) controlled by a sleep mode control signal SLP. The diagnostic clock signal SCLK, the operational clock signal CLK and the sleep mode control signal SLP together provide the control operations for controlling the various elements within the clocked-scan flip-flop 2 to move into and out of sleep mode.

Abstract: A circuit comprises an evaluate clock trace to receive an evaluate clock signal and a precharge clock trace to receive a precharge clock signal. The circuit further comprises sample circuitry coupled to a first signal trace, a second signal trace, the precharge clock trace and the evaluate clock trace to facilitate a detection of a transition on the first signal trace from a first voltage level to a second voltage level. In addition, the circuit comprises latch circuitry coupled to the first signal trace, the second signal trace, the precharge clock trace and the evaluate clock trace to utilize at least a portion of the sample circuitry to maintain voltage levels on the first and the second signal traces when an evaluate clock and a precharge clock are inactive.

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 frequency divider circuit for providing a divided clock signal having a frequency that is an odd integer factor less than the frequency of an incoming system clock signal. The frequency divider includes a clock generator circuit coupled to a delay circuit which operates in an active and a reset phase to provide a divided clock signal from the system clock signal. In the active phase, the clock generator circuit drives the divided clock signal to a first logic state until a reset signal is received. The delay circuit then generates the reset signal at a predetermined number of system clock edges after the divided clock signal is driven to the first logic state. In the reset phase, both the clock generator circuit and the delay circuit are reset in response to the reset signal such that the clock generator circuit immediately drives the divided clock signal to a second logic state, and the delay circuit disables the reset signal within the predetermined number of system clock edges.

Abstract: A scannable latch is disclosed. The scannable latch includes a dynamic circuit, two cross-coupled NAND gates coupled to the dynamic circuit, and a pair of stacked transistors coupled to the dynamic circuit. One of the stacked transistors is for receiving data signals, and the other stacked transistors is for receiving scan in signals.

Abstract: A method of power gating a latch including detecting a state of the latch, detecting a power gate signal, providing power to the latch while the power gate signal is negated, and removing power from the latch when the power gate signal is asserted and the latch is in a predetermined state. The method may include any one or more of pulling a node of the latch to a selected state while the power gate signal is asserted to ensure that the latch powers up in the predetermined state, providing a signal indicative of the latch state and the power gate signal to respective inputs of a logic gate having an output indicative thereof, switching a supply voltage to a power input of the latch based on a state of the output of the logic gate, and closing a switch to pull a node of the latch low.

Abstract: A hardened latch capable of providing protection against single event upsets (SEUs) is disclosed. The hardened latch includes a first latch and a second latch that mirrors a subset of gates of the first latch. The second latch is inserted in the feedback path of the keeper circuit of the first latch and is cross-coupled with the gates of the keeper circuit of the first latch. The latch is hardened against single event upsets and an arbitrary number of successive SEUs attacking a single node, provided that the time between successive SEUs is larger than the recovery time of the latch. An alternate embodiment of the hardened latch includes a split buffer output. This embodiment is capable of reducing the propagation of erroneous transients. Another alternate embodiment of the hardened latch includes a Miller C buffer output. This embodiment is capable of reducing the propagation of erroneous transients below the level achievable in a hardened latch employing a split buffer output.

Abstract: Off-leak electric current is reduced in the operation mode where a circuit is actually operating. In the state in which the power supply voltage is constantly applied to the front stage flip-flops 11 to 13 and rear stage flip-flops 21 to 23, for example, data held in the flip-flops 11 to 13 at rising of the clock signal CK is processed in a logic gate circuit network 31 to which the supply voltage is applied during a low level period of the clock signal CK, and then, the processed data is held in the flip-flops 21 to 23. In the case where the power supply time to the logic gate circuit network 31 is set to minimum, off-leak electric current of the logic gate circuit network 31 can be reduced.

Abstract: Described herein is a latch circuit (110) which has an improved maximum toggle rate or frequency. The latch circuit (110) includes a first portion (116) and a second portion (62) in which input clock signals (52,54) are applied to respective input transistors (118,78). The input transistor (118) for the first portion (116) has an emitter area which is double that of the input transistor (78) for the second portion (62). This ‘imbalance’ between the two input transistors (118,78) provides an increase in the ‘hold period/follow period’ ratio such that it is greater than 1, the self-resonance of the latch circuit (110) and also maximum toggle rate or frequency.

Abstract: A flip-flop (10) comprises a first latch circuit (18), a second latch circuit (24), and a third latch circuit (26). The first latch circuit (18) is coupled to receive a clock signal and a first power supply voltage. The second latch circuit (24) is coupled to the first latch circuit (18) and receives the clock signal and the first power supply voltage. Preparatory to entering a low power mode, the third latch circuit (26) receives a second power supply voltage and is coupled to the second latch circuit (24) in response to a power down signal. During the low power mode, the first power supply voltage is removed from the first and second latch circuits (18, 24). When returning to a normal operating mode, the first power supply voltage is provided to the first and second latch circuits (18, 24), and the third latch circuit (26) is coupled to the first latch circuit (18) in response to a power restore signal.

Abstract: A logic circuit performs an internal level conversion function by driving portions of the circuit with different supply voltages. In one embodiment, first and second stage storage circuits are driven with different supply voltages. In another embodiment, first and second stage storage circuits are driven with a first supply voltage and an inverter coupled to the first stage storage circuit is driven with a second supply voltage. In either case, data transfer into the storage circuits may be controlled by different states of a clock signal. The logic circuit may be a flip-flop circuit, a latch circuit, or another type of circuit.

Abstract: A differential register slave structure is presented. In one embodiment, a differential register includes a storage node (218, 318). The storage node (218, 318) stores and holds the differential values generated by the differential register. In one embodiment of the present invention, on power-up, when the state of various clocks (i.e., master, slave) in the differential register may be indeterminate, the storage node (218, 318) will discharge the differential values and the differential register will produce a differential output.

Abstract: A flip-flop circuit includes a flip-flop, a first pass gate, a second pass gate, and a third pass gate. The first pass gate has an input to receive an input signal, an output coupled to the flip-flop's data input, and a control terminal to receive a first control signal. The second pass gate has an input coupled to the flip-flop's data input, an output coupled to the circuit's output, and a control terminal to receive a second control signal. The third pass gate has an input coupled to the flip-flop's data output, an output coupled to the circuit's output, and a control terminal to receive a third control signal. The first, second, and third control signals may be generated in response to various logical combinations of a bypass signal and a clock enable signal.

Abstract: A flip-flop (10) has a normal mode and a low power mode to save power. The flip-flop (10) has a master latch (14) and a slave latch (20). The slave latch (20) is used to retain the condition of the flip-flop (10) during the low power mode, where power is withdrawn from the master latch (14) but maintained on the slave latch (20). The slave latch (20) may use transistors with lower leakage characteristics than the transistors that make up the master latch (14). These lower leakage characteristics may be achieved by a higher threshold voltage and/or a thicker gate dielectric. Operating speed of the flip-flop (10) is maintained by implementing the slave latch (20) so that no logic gate or switching transistor is in the critical timing path. Instead, the slave latch (20) has an input/output terminal to tap into the signal path between the master latch and an output circuit (22).

Abstract: A differential flip-flop (400) has an output stage (402) with first and second input terminals (X1, X2), first and second output terminals (Q, Qb), a first voltage supply terminal (Vss), a first transistor (435) having a first current-handling terminal connected to the first output terminal (Q), a second current-handling terminal connected to the second output terminal (Qb), and a first control terminal connected to a clock signal (C). A second transistor has a third current-handling terminal connected to the first output terminal (Q), a fourth current-handling terminal connected to the voltage supply terminal (Vss), and a second control terminal connected to a first input terminal (X1) of the output stage. A third transistor (440) has a fifth current-handling terminal connected to the first output terminal (Q), a sixth current-handling terminal connected to the voltage supply terminal (Vss), and a third control terminal connected to the second output terminal (Qb).

Abstract: A flip-flop includes a clock signal input, a data signal input, non-inverting and inverting outputs, a data acceptance unit, and a storage unit having a feedback loop with first and second inverter circuits having feedback to one another. The inverting output is coupled to the first inverter circuit output and the non-inverting output is coupled to the second inverter circuit output. The acceptance unit, dependent upon the data and clock signals present, allocates a programming potential to the first or the second inverter circuit input and applies no potential to the respective other input of the circuits. The acceptance unit has a first switching element applying the predetermined programming potential to the input of the first inverter circuit dependent upon the clock and data signals and a second switching element applying the predetermined programming potential to the second inverter circuit input dependent upon the clock and data signals.

Abstract: CMOS circuitry is partitioned into first and second logic circuit domains. The first logic circuit domain may be optionally a cuttable domains (C_Domains) where circuitry has power supply gating to reduce leakage power and non-cuttable domains (NC_Domains) where circuitry does not have power supply gating. Each output that couples signals from one logic circuit domain to another logic circuit is interfaced with a C_driver and a S_keeper which automatically assure that the output state is held when circuitry is power-gated put to reduce leakage power. The S_keeper and C_driver have low leakage circuits that maintain signal states and are not used for high speed operation.

Abstract: The present invention relates to a differential coder (10) for electrical signals comprising control means (21, 22) and a bistable T adapted to deliver an output binary data signal (S, S*). The bistable T comprises a master bistable (11) followed by a slave bistable (12), each bistable having a main control input (E1, E2). The differential coder is integrated and said control means comprise a first circuit (21) dedicated to the master bistable and adapted to supply said master control signal (A) injected into the main control input of the master bistable and a second circuit (22) dedicated to the slave bistable, controlled by said clock signal (CK) and adapted to supply a slave control signal (CK2) that is representative of a signal that is complementary to the clock signal and is injected into the main control input of the slave bistable.

Abstract: The present invention provides a method of driving a nonvolatile flip-flop circuit comprising the following steps of: a data hold step of holding an input data signal D utilizing polarization of a ferroelectric material of a ferroelectric gate transistor (601) when the data signal D is input while a first clocked inverter (604), a second clocked inverter (603), and a third switching element (602) are turned on and a first switching element (605), a second switching element (607), and a third clocked inverter (608) are turned off; and a data output step of outputting an output signal Q (?Q) based on the held data signal D placing the first clocked inverter (604), the second clocked inverter (603), and the third switching element (602) in the OFF state and placing the first switching element (605), the second switching element (607), and the third clocked inverter (608) in the ON state so as to interrupt an input of a data signal and maintain a polarization state of the ferroelectric material of the ferroelectr

Abstract: A system for reducing current leakage in an integrated circuit. The system includes a first circuit component and a second circuit component in a path between a high voltage state and a low voltage state, such as ground. A feedback mechanism selectively provides feedback from an output of the second circuit component to an input of the first circuit component to selectively cutoff the path at the first circuit when the path is not cutoff at the second circuit. In a more specific embodiment, feedback mechanism preserves data in the integrated circuit via a multiplexer that selectively enables the feedback when the integrated circuit is in sleep mode. The first and second circuit components are High Voltage Threshold (HVT) CMOS inverters. The feedback path is chosen so that when the feedback path is activated, leakage paths through the CMOS inverters are cutoff.

Abstract: Systems and methods provide metastability-resistant techniques. For example, in accordance with an embodiment of the present invention, a flip flop is disclosed having a dynamic gain skewed to provide metastability resistance.

Abstract: State retention registers for use in low-power standby modes of digital IC operation are provided, wherein: a differential circuit (M1–M3; M1–M4) is used to load the shadow latch from the normal functional latch; the signal (REST, RESTZ) used to restore data from the shadow latch to the normal functional latch is a “don't care” signal while the shadow latch is retaining the data during low-power standby mode; retained data from the shadow latch is restored to the normal functional latch via a transistor gate connected to anode (N10) of the shadow latch where the retained data is provided; a power supply (VDD) other than the shadow latch's power supply (VRETAIN) powers the data restore operation; and the normal functional latch is operable independently of the operational states of the high Vt transistors (M1, M2, M5 and M6; M3, M4, M5 and M6) used to implement the state retention functionality.

Abstract: A divider module for use in an oscillation synthesizer includes a plurality of flip-flops and a logic circuit. The plurality of flip-flops is interoperably coupled to produce a divider value based on a control signal. The logic circuit is operably coupled to produce the control signal based on divider select signals. Each of the plurality of flip-flops includes a first differential latch module, a second differential latch module. The first differential latch module is operably coupled to produce a differential latched signal based on a differential flip-flop input signal. The second differential latch module is operably coupled to produce a differential flip-flop output based on the differential latched signal. Each of the first and second differential latch modules includes a sample transistor section, a hold transistor section, a first gating circuit, and a second gating circuit.

Abstract: A flip flop includes a master portion operable to latch at least one of an input signal and an inverted input signal. The flip flop also includes a slave portion operable to latch at least one of the signal latched by the master portion and an inverted signal latched by the master portion in response to a first phase of a clock signal. The slave portion is also operable to be reset in response to a second phase of the clock signal.

Abstract: An embodiment of a ultra low-power data retention latch circuit involves a slave latch SL that concurrently latches the same data that is loaded into a main circuit (such as a main latch ML) during normal operation. When the circuit enters a low power (data retention) mode, power (VCC) to the main latch ML is removed and the slave latch SL retains the most recent data (retained data SA, SA-). When power is being restored to the main latch ML, the slave latch's retained data SA, SA- is quickly restored to the main latch ML through what constitute Set and Reset inputs SAR, SAR- of the ML. This arrangement ensures that data restoration is much quicker than conventional arrangements that require the output data path DATA- to be stabilized before power is re-applied to the main latch. Further, there is no need to wait for power to the ML to be stable before restoring data from the SL to the ML, providing an increase in data restoration speed over conventional data retention latches.

Abstract: A data storage element for use in LSSD compliant circuit designs. The data storage element has an alternate, or scan, data input circuit that has increased immunity to electrical noise while maintaining lower power consumption than the circuits used for primary data input. This increased noise immunity reduces the probably that noise on the alternate data input will cause an unintended change of data state stored in the data storage element. Modification of latch circuits used in the data storage element allow a reduction in the number of transistors used in the latch circuits, thereby compensating for the increase in transistors used in the alternate data input circuit and allowing the data storage element to use the same number of transistors as prior designs that have less noise immunity on their alternate data inputs.

Abstract: An integrated circuit that converts a single rail signal into a dual-rail signal includes a clock signal connection, a data input to which a single-rail signal is applied, a data output on which a dual-rail signal is tapped off on output lines, and a converter, which is connected between the data input and the data output, that converts the single-rail signal into the dual-rail signal. The converter includes a memory cell having an input connected to the data input and output connections, wherein in a transparent state, the output connections provide the logically valid dual-rail signal, and a circuit arrangement, which is arranged between the output connections of the memory cell and the data output of the integrated circuit, that precharges the output lines connected to the output connections, and ensures a direct transition from a precharge phase to a logic state on the output lines, and vice versa.

Abstract: Briefly, in accordance with one embodiment of the invention, a flip-flop operates as a master-slave flip flop in a test mode and operates as a pulsed latch in normal operation. Two clock signals having non-overlapping transitions are used to provide and control the flow of input data.

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 state saving circuit includes a state saving latch powered by an un-interruptible power supply, and a cut-off control device powered by the un-interruptible power supply that selectively connects the state saving latch to a pair of latch nodes based upon a control signal. The control signal determines whether the state-saving latch is in one of a state saving mode and a state restoring mode.

Abstract: An apparatus comprising a low voltage swing (LVS) circuit having a plurality of alternating LVS pre-charging and evaluation phases and a select logic circuit coupled to the LVS circuit and responsive to a plurality of input data signals to generate a plurality of select signals for the LVS circuit. Each of the select signals occurs during one of the LVS evaluation phases and has a turning-on edge and a turning-off edge. The turning-off edge of each of the select signals is generated independent of the input data signals.

Abstract: Methods for implementing familiar electronic circuits at nanoscale sizes using molecular-junction-nanowire crossbars, and nanoscale electronic circuits produced by the methods. In one embodiment of the present invention, a 3-state inverter is implemented. In a second embodiment of the present invention, two 3-state inverter circuits are combined to produce a transparent latch. The 3-state inverter circuit and transparent-latch circuit can then be used as a basis for constructing additional circuitry, including master/slave flip-flops, a transparent latch with asynchronous preset, a transparent latch with asynchronous clear, and a master/slave flip-flop with asynchronous preset.

Abstract: A flip-flop circuit includes a master latch and a slave latch, where a latch operation of the slave latch is controlled by a comparison result between an output signal of the master latch and an output signal of the slave latch. For example, a master latch gate receives an input signal and outputs the input signal under control of a clock signal and an inverted clock signal. A master latch receives the signal output by the master latch gate and latches the signal output by the master latch gate under control of the clock signal and the inverted clock signal. A slave latch gate receives the signal latched by the master latch and outputs the signal latched by the master latch under control of the clock signal and the inverted clock signal. A slave latch receives the signal output by the slave latch gate and latches the signal output by the slave latch gate under control of a slave latch control signal and an inverted slave latch control signal.

Abstract: The invention includes digital logic devices with extremely skewed trip points and reset circuitry for rapidly propagating signal edges. Embodiments of skewed logic devices in accordance with the present invention include inverters, buffers, NOR gates and NAND gates for rapidly propagating a selected “fast” edge of an input signal. Additional embodiments include pulse stretchers, memory devices, substrates, computer systems and methods incorporating the skewed logic devices of the present invention. Each embodiment of a skewed logic device of the present invention is configured to propagate either a fast rising edge or fast falling edge of an output signal, i.e., the “fast” edge, at rates comparable to those of domino logic. An advantage of the skewed logic devices of the present invention over conventional CMOS logic devices is rapid edge propagation. Additionally, virtually all of the input gate loading is devoted to the fast edge being propagated.

Abstract: A multiple trip point fuse latch device and method is disclosed. Multiple read inputs to a fuse latch enable the altering of the resistive trip point of the fuse latch. A multiple trip point fuse latch may be combined with a slave latch to form a master-slave flip-flop, and multiple master-slave flip-flops may be connected in series to form a shift register. Changing the trip point permits the use of a test procedure that may analyze the margins of a fuse latch during the fuse read operation.

Abstract: In a scan flip-flop circuit, a first master latch circuit receives usual mode data at a usual data input terminal in synchronization with a first clock signal. A second master latch circuit receives scan-in data at a scan-in data input terminal in synchronization with first and second scan clock signals. A slave latch circuit receives an output signal of the first master latch circuit in synchronization with said first clock signal and the second scan clock signal. The slave latch circuit is constructed by a control circuit for controlling transfer of the usual mode data to the output terminal in synchronization with the second scan clock signal.

Abstract: The present invention relates to a flip-flop circuit employing an MTCMOS technology comprising a master latch unit and a slave latch unit, for latching input data and outputting the data under the control of an internal clock signal, wherein an output of the flip-flop circuit retains a state just before the admission to sleep mode when the state of the system is converted from sleep mode to active by means of making a data state of an input terminal of a master latch into the same state as an inversed data state of an input terminal of a slave latch circuit in sleep mode and storing it. The flip-flop circuit employing the MTCMOS technology in accordance with the present invention is capable of retaining a state just before the sleep mode when the state of the system is converted from sleep mode to active mode by using the sleep mode control signal by means of adding the feedback circuit to the conventional flip-flop circuit.

Abstract: A low power flip-flop is disclosed. The number of transistors which are coupled to the clock signal is reduced by more than half when compared with known flip-flop designs. The flip-flop comprises a pair of clocked transistors forming a pass gate and a plurality of inverters coupled thereto. By reducing the number of clock signal connections needed for reliable operation, the present invention reduces the power consumed by the flip-flop when operating at typical levels of activity by up to 70%.

Abstract: A clocked-scan flip-flop for multi-threshold CMOS (MTCMOS) is provided. The clocked-scan flip-flop includes a first switching unit which switches normal data that are input from the outside and outputs the data; a second switching unit which switches scan data that are input from the outside and outputs the data; a latch unit which latches the data input from the first switching unit or the second switching unit; and a clock input unit which controls the switching operations of the first and second switching units according to the result of a predetermined operation on a clock signal and a scan clock signal that are input from the outside. The clocked-scan flip-flop has the characteristics of a complementary pass-transistor (CP) flip-flop, that is, low power consumption and high performance. Also, the clocked-scan flip-flop provides a full-scale scan function for test purposes.

Abstract: A data latch system includes a data input for providing a first data bit having a first duration and a second data bit having a second duration, and a data output for providing the first data bit for the first and second durations. First sampling circuitry is connected to the data input and the data output for the first duration to provide the first data bit to the data output. Second sampling circuitry is connected to the data input and the data output for the second duration to provide the second data bit inverted to the data output. Holding circuitry connected to the data output for the second duration holds the first data bit and the second sampling circuitry connects the second data bit inverted to the data output to enhance the held first data bit when the first and second data bits have different states.

Abstract: This invention describes circuit techniques providing a means for achieving reliable data retention and low leakage current in single step latches with switch transistors. The techniques require changes only in the circuit configuration. Neither higher cost technology such as multiple-threshold LVT/HVT transistors nor special control circuits are needed.

Abstract: In response to a first transition of a clock signal, an information signal having a logic state is received. In response to a second transition of the clock signal, first circuitry latches a logic state of a first signal that indicates the information signal's logic state. In response to a third transition of the clock signal, second circuitry latches a logic state of a second signal that indicates the first signal's logic state. During a first mode of operation, power is supplied to the first and second circuitry. During a second mode of operation, power is reduced to the first circuitry, while power is supplied to the second circuitry, so that the first signal's logic state is lost, while the second signal's logic state is preserved.

Abstract: Described are high-speed differential flip-flops. A flip-flop in accordance with one embodiment incorporates some combinational logic, eliminating the need for separate combinational logic when the flip-flop is employed in certain circuit configurations. A flip-flop in accordance with another embodiment includes differential input and output stages, each of which includes a transistor connected across its differential output terminals. The transistors are clocked to short the differential output terminals between expressions of logic levels, thereby limiting the maximum amount of voltage swing required to express subsequent logic levels.

Abstract: A low power, high speed D type flip flop is disclosed. The D type flip flop uses four inverters and four transmission gates to store and output the data states. The flip flop comprises two memory elements wherein each memory element is made up of a transmission gate and two inverters. Each of the four inverters contained in the flip flop is referred to as a bypass current limiting inverter. Each of the four inverters contains biasing circuitry to limit current flow and thereby save power. Additionally, each inverter has switching circuitry that enables the current limiting features to be automatically and advantageously bypassed thereby allowing for large currents and fast response times whilst simultaneously retaining the low power performance.

Abstract: A differential latch circuit with a differential reset function includes a first arrangement of transistors configured to perform a latch function and a second arrangement of transistors, connected to the first arrangement of transistors, configured to perform a reset function. The first arrangement of transistors includes branches having three cascoded transistors, and the second arrangement of transistors includes branches having two cascoded transistors. This configuration enables the latch circuit to use lower power supply voltages relative to conventional latch circuits that require four more cascoded transistors.

Abstract: An integrated circuit including a Multi-Threshold CMOS (MTCMOS) latch combining low voltage threshold CMOS circuits with high voltage threshold CMOS circuits. The low voltage threshold circuits including a majority of the circuits in the signal path of the latch to ensure high performance of the latch. The latch further including high voltage threshold circuits to eliminate leakage paths from the low voltage threshold circuits when the latch is in a sleep mode. A single-phase latch and a two-phase latch are provided. Each of the latches is implemented with master and slave registers. Data is held in either the master register or the slave register depending on the phase or phases of the clock signals. A multiplexer may alternatively be implemented prior to the master latch for controlling an input signal path during sleep and active modes of the latch and for providing a second input signal path for test.

Abstract: In an integrated circuit, a time-axis expanding circuit is provided in addition to a driver circuit for outputting a signal outside. The time-axis expanding circuit has an equivalent receiver circuit similar to an ordinary receiver circuit, and a D-type flip-flop circuit connected to the equivalent receiver circuit. Input signals from the pins of the time-axis expanding circuit are inputted to the gates of CMOS transistors of the equivalent receiver circuit, and equivalent differential receiving signals outputted from the drains of the CMOS transistors are inputted to the D input terminal of the D-type flip-flop circuit. A measuring clock signal is inputted to the clock input terminal of the D-type flip-flop circuit, and a time-axis-expanded signal is outputted from the Q output terminal of the D-type flip-flop circuit to an output terminal of the time-axis expanding circuit.