(b) To get the Signed_Overflow bit (in the following module aluOV) for a 4-bit adder, we can XOR the carry bit C3 (to the MSB slice) with the carry bit C4 (from the MSB slice), see figure Q4-2. Compose HDL code to get C3, C4 and then output Signed_Overflow signal, with necessary comments.

Sure, here is the HDL code for the aluOV module:

module aluOV(A, B, Cin, Signed_Overflow, C3, C4);

input [3:0] A, B;
input Cin;
output Signed_Overflow;
output C3, C4;
wire [3:0] Sum;
wire C0, C1, C2, C3_int, C4_int;

// Full adder for LSB slice
full_adder FA0(Sum[0], A[0], B[0], Cin, C0);

// Full adder for second bit slice
full_adder FA1(Sum[1], A[1], B[1], C0, C1);

// Full adder for third bit slice
full_adder FA2(Sum[2], A[2], B[2], C1, C2);

// Full adder for MSB slice
full_adder FA3(Sum[3], A[3], B[3], C2, C3_int);

// Calculate C3 and C4
assign C3 = C3_int ^ C4_int;
assign C4 = C3_int;

// Calculate signed overflow
assign Signed_Overflow = (A[3] == B[3]) && (A[3] != Sum[3]);

endmodule

// Full adder module
module full_adder(Sum, A, B, Cin, Cout);

input A, B, Cin;
output Sum, Cout;

assign Sum = A ^ B ^ Cin;
assign Cout = (A & B) | (Cin & (A ^ B));

endmodule

Here, we use four full adders to perform the 4-bit addition, and then use XOR gates to compute the C3 and C4 carry bits. Finally, we use the formula for signed overflow to calculate the output signal.