S$1,$ S$0$ select which Input is presented to output.

The values of $In[3.\mathrm{.}0]$ are stored and preserved every clock cycle and sent to Out$[3.\mathrm{.}0]$

NOTE: $([$n$.\mathrm{.}0])$ is equivalent to bits from $(n,n-1,n-2,$dots$2,1,0)$ included in values.

$$

Each clock pulse the output values for Q$3$ moves to Q$2,$ Q$2$ to Q$1,$ Q$1$ to Q$0,QO$ will disappear; Input will also replace Q$3$ after it is moved.

S$1,$ S$0$ select which Input is presented to output.

The values of $In[3.\mathrm{.}0]$ are stored and preserved every clock cycle and sent to Out$[3.\mathrm{.}0]$

NOTE: $([$n$.\mathrm{.}0])$ is equivalent to bits from $(n,n-1,n-2,$dots$2,1,0)$ included in values.

$$

Each clock pulse the output values for Q$3$ moves to Q$2,$ Q$2$ to Q$1,$ Q$1$ to Q$0,QO$ will disappear; Input will also replace Q$3$ after it is moved.