module top (
    // USB Port
    inout  wire usb_dp,
    inout  wire usb_dn,
    inout  wire usb_pu,

    // LEDs
    output wire [2:0] leds
);

    // Signals
    // -------

    // USB
    wire usb_dp_o,  usb_dn_o;
    wire usb_dp_oe, usb_dn_oe;
    wire usb_dp_i,  usb_dn_i;
    wire usb_pu_oe;

    // Clock / Reset
    wire rst_i, rst;
    wire clk_i, clk;



    reg [23:0] cnt;

    always @(posedge clk)
        if (rst)
            cnt <= 0;
        else
            cnt <= cnt + 1;

    assign leds = cnt[23:21];

    assign usb_dp_o  = 1'b0;
    assign usb_dn_o  = 1'b0;
    assign usb_dp_oe = 1'b0;
    assign usb_dn_oe = 1'b0;



    // Clock / Reset
    // -------------

    qlal4s3b_cell_macro u_qlal4s3b_cell_macro (
        .Sys_Clk0    (clk_i),
        .Sys_Clk0_Rst(rst_i)
    );

    gclkbuff gbuf_clk_I (
        .A(clk_i),
        .Z(clk)
    );

    gclkbuff gbuf_rst_I (
        .A(rst_i),
        .Z(rst)
    );


    // IOB
    // ---

    bipad io_usb_data_I (
        .P ({usb_dp,    usb_dn}),
        .A ({usb_dp_o,  usb_dn_o}),
        .EN({usb_dp_oe, usb_dn_oe}),
        .Q ({usb_dp_i,  usb_dn_i})
    );

    bipad io_usb_pu_I (
        .P(usb_pu),
        .A(1'b1),
        .EN(usb_pu_oe)
    );

endmodule