An integrated circuit includes a first time delay circuit, a second time delay circuit, and a master-slave flip-flop having a gated input circuit and a transmission gate. The first time delay circuit has a first input configured to receive a first clock signal and having a first output configured to generate a second clock signal. The second time delay circuit has a second input configured to receive the second clock signal and having a second output configured to generate a third clock signal. The transmission gate is configured to receive the first clock signal and the second clock signal to control a transmission state of the transmission gate. The gated input circuit is configured to have an input transmission state controlled by the third clock signal at the second output of the second time delay circuit.

A scan chain architecture with lowered power consumption comprises a multiplexer selecting between a functional input and a test input. The output of the multiplexer is coupled to a low threshold voltage latch and, in test mode, to a standard threshold voltage latch. The low threshold voltage latch and standard threshold voltage latch are configured to store data when a clock input falls, using a master latch functional clock M_F_CLK, master latch test clock M_T_CLK, slave latch functional clock S_F_CLK, and slave latch test clock S_T_CLK. The slave latch has lower power consumption than the master latch.

An apparatus includes a master latch circuit including a first circuit and a second circuit, and a slave latch circuit including a third circuit and a fourth circuit. The first circuit and the second circuit may be coupled to a first shared circuit node, and the third circuit and the fourth circuit may be coupled to a second shared circuit node. The master latch circuit may be configured to store a value of an input signal in response to an assertion of a clock signal. The slave latch circuit may be configured to store an output value of the master latch circuit in response to a de-assertion of the clock signal. The master latch circuit may also be configured to de-couple the first shared circuit node from a ground reference node in response to the de-assertion of the clock signal.

Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C.sup.3MOS) 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 C.sup.3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C.sup.3MOS logic with low power conventional CMOS logic. The combined C.sup.3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C.sup.3MOS) 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 C.sup.3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C.sup.3MOS logic with low power conventional CMOS logic. The combined C.sup.3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

A method of forming a semiconductor device includes forming active regions, forming S/D regions, forming MD contact structures and forming gate lines resulting in corresponding transistors that define a first time delay circuit having a first input configured to receive a first clock signal and having a first output configured to generate a second clock signal from the first clock signal; and corresponding transistors that define a second time delay circuit having a second input configured to receive the second clock signal and having a second output configured to generate a third clock signal from the first clock signal; forming a first gate via-connector in direct contact with the first gate line atop the first-type active region in the first area; and forming a second gate via-connector in direct contact with the second gate line atop the second-type active region in the second area.

A method of forming a semiconductor device includes forming active regions, forming S/D regions, forming MD contact structures and forming gate lines resulting in corresponding transistors that define a first time delay circuit having a first input configured to receive a first clock signal and having a first output configured to generate a second clock signal from the first clock signal; and corresponding transistors that define a second time delay circuit having a second input configured to receive the second clock signal and having a second output configured to generate a third clock signal from the first clock signal; forming a first gate via-connector in direct contact with the first gate line atop the first-type active region in the first area; and forming a second gate via-connector in direct contact with the second gate line atop the second-type active region in the second area.

A flip-flop with glitch protection is disclosed. The flip-flop includes a differential amplifier circuit that generates amplifier output signals based on an input data and clock signals and precharges a true data node when a clock signal is inactive. A latch circuit is coupled to the differential amplifier and includes a latch node. Responsive to a current value of the input data signal having a first logic state, the latch node is set at a logic value equivalent to the precharged value during an active phase of the clock signal. Responsive to the current value of the input data signal having a second logic state complementary to the first, during the active phase of the clock signal, the latch circuit causes the latch node to be set to a logic value complementary to the precharged value, using the clock signal and the current value of the input data signal.

A receiver includes a first transfer gate, a first inverter, a second inverter, a second transfer gate, a third inverter, and a fourth inverter connected in series, a first power supply supplying power to the first and second inverters, a second power supply supplying power to the third and fourth inverters, a third power supply supplying power to the second transfer gate, first and second signals having opposite logic levels for controlling the first transfer gate. The third power supply is significantly lower than the first or second power supply. The leakage current of the receiver is significantly reduced in the core when the second power supply remains on but the first power supply is turned off while the performance of the receiver remains the same.

Multi-bit data flip-flops are disclosed that provide bit initialization through propagation of scan bits. Input multiplexers are configured to select between input data bits and input scan bits based upon mode select signals. Master latches receive and latch outputs from the input multiplexers. Slave latches receive and latch outputs from the master latches and also provide propagated input scan bits to the input multiplexers. A first state for the mode select signals selects the input data bits for a data mode of operation, and a second state for the mode select signals selects the input scan bits for a scan mode of operation. Further, the input multiplexers, master latches, and slave latches are configured to operate in an initialization mode to pass a fixed input scan bit through the multi-bit data flip-flop based upon initialization signals (e.g., set and/or reset signals).