9. XOR Gate Using Basic Gates

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);
    assign y = ~a;

endmodule

// ============================================================
// XOR Gate
// ============================================================
module xor_gate (
    input  a, b,
    output y
);
    wire nota, notb, t1, t2;

not_gate n1 (.a(a), .y(nota));     // nota = ~a
not_gate n2 (.a(b), .y(notb));     // notb = ~b

and_gate a1 (.a(a), .b(notb), .y(t1));   // t1 = a & ~b
and_gate a2 (.a(nota), .b(b), .y(t2));  // t2 = ~a & b

or_gate o1 (.a(t1), .b(t2), .y(y));     // y = t1 | t2 = (a & ~b) | (~a & b)

endmodule