source: sandbox/MultiChannelUSB/counter.v@ 180

module counter
        (
                input   wire                    clock, frame,

                input   wire                    reset, setup, count,

                input   wire                    bus_ssel, bus_wren,
                input   wire    [1:0]   bus_addr,
                input   wire    [15:0]  bus_mosi,

                output  wire    [15:0]  bus_miso,
                output  wire                    bus_busy,
                
                output  wire                    cnt_good
        );

        wire    [3:0]   int_ssel_wire;
        wire    [15:0]  int_miso_wire;

        reg                             cnt_good_reg;
        reg             [15:0]  int_miso_reg;

        wire    [63:0]  reg_bits_wire;
        wire    [63:0]  cnt_bits_wire;
        
        reg                             int_load_reg;

        integer i;
        genvar j;

        lpm_counter     #(
                .lpm_direction("DOWN"),
                .lpm_port_updown("PORT_UNUSED"),
                .lpm_type("LPM_COUNTER"),
                .lpm_width(64)) lpm_counter_component (
                .sload(int_load_reg | setup),
                .sclr(reset),
                .clock(clock),
                .data(reg_bits_wire),
                .cnt_en((frame) & (count) & (|cnt_bits_wire)),
                .q(cnt_bits_wire));

        generate
                for (j = 0; j < 4; j = j + 1)
                begin : BUS_OUTPUT
                        lpm_ff #(
                                .lpm_fftype("DFF"),
                                .lpm_type("LPM_FF"),
                                .lpm_width(16)) cfg_reg_unit (
                                .enable(int_ssel_wire[j] & bus_ssel & bus_wren),
                                .sclr(reset),
                                .clock(clock),
                                .data(bus_mosi),
                                .q(reg_bits_wire[j*16+15:j*16]));
                                end
        endgenerate

        lpm_mux #(
                .lpm_size(4),
                .lpm_type("LPM_MUX"),
                .lpm_width(16),
                .lpm_widths(2)) bus_miso_mux_unit (
                .sel(bus_addr),
                .data(cnt_bits_wire),
                .result(int_miso_wire));


        lpm_decode #(
                .lpm_decodes(4),
                .lpm_type("LPM_DECODE"),
                .lpm_width(2)) lpm_decode_unit (
                .data(bus_addr),
                .eq(int_ssel_wire));

        always @(posedge clock)
        begin
                if (reset)
                begin
                        int_miso_reg <= 16'd0;
                        cnt_good_reg <= 1'b0;
                        int_load_reg <= 1'b0;
                end
                else
                begin
                        int_miso_reg <= int_miso_wire;
                        cnt_good_reg <= |cnt_bits_wire;
                        int_load_reg <= bus_ssel & bus_wren;
                end
        end

        // output logic
        assign  bus_miso = int_miso_reg;
        assign  bus_busy = 1'b0;
        assign  cnt_good = cnt_good_reg;

endmodule