Patent ID: 7590900

Claim:
A pulse-based flip flop which outputs a scan input signal and a data signal, the flip-flop comprising: a pulse generator to generate a pulse signal for coordinating operation of the flip flop, the pulse signal includes only a non-inverted pulse signal and an inverted pulse signal; a multiplexer to receive the data signal, the scan input signal, and a scan enable signal, and to selectively output one of the data signal and the scan input signal in response to the scan enable signal, wherein the multiplexer performs the operation of selective outputting irrespective of the non-inverted pulse signal and the inverted pulse signal; and a latch unit to transfer therethrough the data signal or the scan input signal received from the multiplexer according to the non-inverted pulse signal and the inverted pulse signal, wherein the latch unit latches the data signal or the scan input signal received from the multiplexer through a common latching path, wherein the latch unit includes: a switching circuit connected between the multiplexer and a node, the switching circuit being arranged to selectively transfer one of the data signal and the scan input signal received from the multiplexer to the node according to an activation of one of the inverted pulse signal and the non-inverted pulse signal; an output circuit connected to the node; and a voltage maintenance type of circuit loop connected to the node, the voltage maintenance type of circuit loop being arranged to selectively maintain a voltage at the node according to an activation of the other of the one of the inverted pulse signal and the non-inverted pulse signal being activated for selectively transferring one of the data signal and the scan input signal.