An electrical circuit includes a flip-flop, a first multiplexer, a second flip-flop, a third flip-flop, and output storage element including a second multiplexer and a fourth flip-flop. The first flip-flop, clocked functional clock signal, receives a functional signal. The first multiplexer receives the output of the first flip-flop and a test mode shift-in signal, and outputs one of them based on the state of a select input. The second flip-flop, clocked by a test clock signal, receives the output of the first multiplexer. The third flip-flop, clocked by a second test clock signal, receives the output of the second flip-flop. The second multiplexer receives the functional signal and the output of the third flip-flop, and outputs one of them based on a mode select input signal. The fourth flip-flop, clocked by a pulse-controlled functional clock signal, receives the output of the second multiplexer.