Simulate the program by showing signals $x,Y,S,V,N,$ and Z using the following cases:

a$.x=+2$ and $Y=+1$

b$.x=+5$ and $Y=+2$

c$.x=-7$ and $Y=+2$

d$.x=+4$ and $Y=+4$

e$.x=+5$ and $Y=+4$rigure $5\mathrm{.}43$

A comparaior circuit.

module comparator $(x,Y,V,N,Z)$; input $[3$:$0]x,Y$;

output $V,N,Z$;

wire $[3$:$0]S$;

wire $[4$:$1]C$;

fulladd stage$0(1\text{'}$b$1,$ X$[0],$Y$[0],$ S$[0],$ C$[1])$;

fulladd stage $1($C$[1],$ X$[1],$Y$[1],$ S$[1],$ C$[2])$;

fulladd stage $2($C$[2],$ X$[2],$Y$[2],$ S$[2],$ C$[3])$;

fulladd stage$3($C$[3],$ X$[3],$Y$[3],$ S$[3],$ C$[4])$;

assign $V=C[4{]}^C[3]$;

assign $N=S[3]$;

assign $Z=!S$;

endmodule

module fulladd $($Cin$,x,y,s,$ Cout$)$;

input $C$ in$,x,y$;

output s$,$ Cout;

assign $s=x^y{?}^{{?}^{?}}$Cin;

assign Cout $=(x$&$y)|(x$&Cin$)|(y$&Cin$)$;

endmodule