A master-slave flip-flop includes a master latch, a slave latch, a first logic gate and a signal transition detector. The first logic gate is receiving a reference clock and a first control clock, and outputting a first trigger signal to control one of the master latch and the slave latch, which are connected with a logic circuit, to switch to an opaque state or a transparent state, wherein the other one of the master latch and the slave latch is switched to an opaque state or a transparent state according to the reference clock. The above-mentioned master-slave flip-flop can correct sampling when a timing error occurs.

A flip-flop circuit configured to latch an input signal to an output signal is disclosed. The circuit includes a first latch circuit; and a second latch circuit coupled to the first latch circuit. In some embodiments, in response to a clock signal, the first and second latch circuits are complementarily activated so as to latch the input signal to the output signal, and the first and second latch circuits each comprises at most two transistors configured to receive the clock signal.

Described is a latch which comprises: a first AND-OR-invert (AOI) logic gate; and a second AOI logic gate coupled to the first AOI logic gate, wherein the first and second AOI logic gates have respective first and second keeper devices coupled to a power supply node. Described is a flip-flop which comprises: a first latch including: a first AOI logic gate; and a second AOI logic gate coupled to the first AOI logic gate, wherein the first and second AOI logic gates have respective first and second keeper devices coupled to a power supply, the first latch having an output node; and a second latch having an input node coupled to the output node of the first latch, the second latch having an output node to provide an output of the flip-flop.

In an aspect of the disclosure, a method and an apparatus are provided. The apparatus is a register array including first and second flip-flop latch arrays. The first flip-flop latch array includes a first set of master latches, a first set of slave latches coupled to the first set of master latches, and a first address port. The second flip-flop latch array includes a second set of master latches, a second set of slave latches coupled to the second set of master latches, and a second address port. The register array includes an address counter, coupled to the first flip-flop latch array and the second flip-flop latch array. The address counter is shared by the first flip-flop latch array and the second flip-flop latch array and configured to address, in parallel in a test mode, the first flip-flop latch array through the first address port and the second flip-flop latch array through the second address port.

A non-volatile flip flop integrated circuit includes a master latch circuit, a slave latch circuit coupled to the master latch circuit, and a non-volatile memory array coupled to the slave latch circuit. The non-volatile memory array includes a first pair of memory cells coupled to the slave latch circuit, and a second pair of memory cells coupled to the slave latch circuit in parallel with the first pair of memory cells. The first and second pair of memory cells are configured to store data from the slave latch circuit, and to restore data to the slave latch circuit.

The invention relates to devices and methods of maintaining the current starved delay at a constant value across variations in voltage and temperature to increase the speed of operation of the sequential logic in the radiation hardened ASIC design.

Aspects include a computer-implemented method for initializing scannable and non-scannable latches from a clock buffer. The method includes receiving a clock signal; receiving control signals including a hold signal, a scan enable signal, and a non-scannable latch force signal; responsive to receiving a low input from the hold signal and the scan enable signal, outputting a high signal from a functional clock port on a next cycle; responsive to receiving a high input from the scan enable signal and a low input from the hold signal, outputting a high slave latch scan clock signal on the next cycle; responsive to receiving a high input from the hold signal and the scan enable signal, outputting a high master latch clock signal on the next clock cycle; and responsive to receiving a high input from the non-scannable latch force signal, outputting a low master latch clock signal on a current cycle.

An input buffer chooses, in accordance with first control clocks, to output an input data signal or output a high-impedance signal. A master flip-flop chooses, in accordance with second control clocks, to output a data signal received from the input buffer or retain a currently output data signal. A master-slave switch chooses, in accordance with the second control clocks, to output a high-impedance signal or output a data signal received from the master flip-flop. A slave flip-flop chooses, in accordance with the second control clocks, to retain a currently output data signal or output a data signal received from the master-slave switch. A clock buffer inputs the second control clocks, and generates and outputs the first control clocks.

A flip-flop structure comprising a master latch and a slave latch. An output of an input stage of the master latch is coupled to the output of the master latch. The input stage is arranged to drive a logical state at the output of the master latch corresponding to a logical state of the received data input signal during a first phase of a clock signal. A feedback component is arranged to sample a logical state at the output of the master latch and to drive a logical state at the output of the master latch based on the sampled logical state at the output of the master latch such that the sampled logical state is maintained, during a second phase of the clock signal.

A circuit including a logic gate responsive to a clock signal and to a control signal. The circuit also includes a master stage of a flip-flop. The circuit further includes a slave stage of the flip-flop responsive to the master stage. The circuit further includes an inverter responsive to the logic gate and configured to output a delayed version of the clock signal. An output of the logic gate and the delayed version of the clock signal are provided to the master stage and to the slave stage of the flip-flop. The master stage is responsive to the control signal to control the slave stage.