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 w1,w2,w3,w4;
    not_gate a1 (b,w1);
    not_gate a2 (a,w2);
    and_gate n1 (a,w1,w3);
    and_gate n2 (w2,b,w4);
    or_gate o1 (w3,w4,y);

    // TODO: instantiate required gates

endmodule