$8*$ The serial adder of Fig. $6\mathrm{.}6$ uses two four$-$bit registers. Register A holds the binary number $0101$ and register ${?}^{TT}B$ holds $0111.$ The carry flip$-$flop is initially reset to $0.$ List the binary values in register A and the carry flip$-$flop after each shift. $($HDL$-$see Problem $6\mathrm{.}54).$