How do you plan to solve it?
// ============================================================
// Basic Gates (given)
// ============================================================
module and_gate(input a, b, output y);
assign y = a & b;
endmodule
module or_gate(input a, b, output y);
assign y = a | b;
endmodule
module not_gate(input a, output y);
// write code here for not gate
assign y = ~a;
endmodule
// ============================================================
// XOR Gate
// ============================================================
module xor_gate (
input a, b,
output y
);
// TODO: declare intermediate wires
not_gate not_a(.a(a),.y(na));
not_gate not_b(.a(b),.y(nb));
and_gate and1(.a(a),.b(nb),.y(anb));
and_gate and2(.a(na),.b(b),.y(nab));
or_gate or1(.a(anb),.b(nab),.y(y));
// TODO: instantiate required gates
endmodule