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);
    // 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 not_a,not_b;
    wire a_and_not_a,b_and_not_a;

    not_gate n1(.a(a),.y(not_a)); // y=~a
    not_gate n2(.a(b),.y(not_b)); // y=~b

    and_gate a1(.a(a), .b(not_b), .y(a_and_not_b)); 
    and_gate a2(.a(not_a), .b(b), .y(not_a_and_b));

    or_gate o1(.a(a_and_not_b), .b(not_a_and_b), .y(y));


endmodule