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);
// write code here for or gate
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
);
wire bbar,y1,abar,y2;
// TODO: declare intermediate wires
not_gate n1(.a(b),.y(bbar));
and_gate a1(.a(a),.b(bbar),.y(y1));
not_gate n2(.a(a),.y(abar));
and_gate a2(.a(abar),.b(b),.y(y2));
or_gate o1(.a(y1),.b(y2),.y(y));
// TODO: instantiate required gates
endmodule