working k.i.t.t. example

module top (clk_in, pushbutton, resetbutton, allonbutton, altbutton, kittbutton, leds);

    input    wire        clk_in;
    input    wire        pushbutton;
    input    wire        resetbutton;
    input    wire        allonbutton;
    input    wire        altbutton;
    input    wire        kittbutton;
    output   wire[7:0]   leds;

    // Input clock 50 mhz (board has an oscillator, not just a crystal)
    wire                clk1;    // 400 MHz
    wire                clk2;    // 200 MHz
    wire                clkOk;

     // Push the 50 mhz clock into a PLL and have it generate 400 and 25 mhz clocks.
    // You can modify the generated frequencies by clicking on the pll.ipx file in Diamond
    // modifying values in the GUI and regenerating.
    pll pll100 (.CLK(clk_in), .CLKOP(clk1), .CLKOK(clk2), .LOCK(clkOk));

    slow_counter counter(.clock(clk1), .enable(pushbutton), .reset(resetbutton), .all_on(allonbutton), .alt(altbutton), .kitt(kittbutton), .output_byte(leds));

endmodule

module slow_counter (clock, enable, reset, all_on, alt, kitt, output_byte);

    input wire clock;
    input wire enable;
    input wire reset;
    input wire all_on;
    input wire alt;
    input wire kitt;
    output reg[7:0] output_byte;

    reg [31:0]   counter;
    reg [7:0]    kittlight;
    reg [31:0]   kittcounter;
    reg [4:0]    kittstep;
    reg          kittdirection;

    initial
    begin
        output_byte      = 8'b11111111;
        kittlight        = 8'b00000001;
        kittcounter      = 32'b0;
        kittstep         = 32'b0;
        kittdirection    = 1'b1;
        counter          = 32'b0;
    end

    always @(posedge clock)
    begin
        if (reset == 1'b0)
        begin
            counter <= 32'b0;
            output_byte <= ~counter[23:16];
        end
        else if (all_on == 1'b0)
        begin
            counter <= 32'b11111111111111111111111;
            output_byte <= ~counter[23:16];
        end
        else if (kitt == 1'b0)
        begin
            counter <= 32'b10101010101010101010101;
            output_byte <= ~counter[23:16];
        end
        else if (alt == 1'b0)
        begin
            // Increase our counter
            kittcounter <= kittcounter + 1'b1;
            if (kittcounter[16] == 1'b1)
            begin
                // Reset the counter
                kittcounter <= 32'b0;

// Note:  I tried using various syntaxes for a shift and none worked:  kittlight[7:0] <= (kittlight[7:0] << 1'b1);
// Note:  I added a double-light for my son to see
                // Are we going left or right?
                if (kittdirection == 1'b1)
                begin
                    // Going left
                    if (kittstep == 0) begin
                        kittlight <= 8'b10000001;
                    end
                    else if (kittstep == 1) begin
                        kittlight <= 8'b01000010;
                    end
                    else if (kittstep == 2) begin
                        kittlight <= 8'b00100100;
                    end
                    else if (kittstep == 3) begin
                        kittlight <= 8'b00011000;
                    end
                    else if (kittstep == 4) begin
                        kittlight <= 8'b00011000;
                    end
                    else if (kittstep == 5) begin
                        kittlight <= 8'b00100100;
                    end
                    else if (kittstep == 6) begin
                        kittlight <= 8'b01000010;
                    end
                    else if (kittstep == 7) begin
                        kittlight <= 8'b10000001;
                    end
                end
                else
                begin
                    // Going right
                    if (kittstep == 0) begin
                        kittlight <= 8'b10000001;
                    end
                    else if (kittstep == 1) begin
                        kittlight <= 8'b01000010;
                    end
                    else if (kittstep == 2) begin
                        kittlight <= 8'b00100100;
                    end
                    else if (kittstep == 3) begin
                        kittlight <= 8'b00011000;
                    end
                    else if (kittstep == 4) begin
                        kittlight <= 8'b00011000;
                    end
                    else if (kittstep == 5) begin
                        kittlight <= 8'b00100100;
                    end
                    else if (kittstep == 6) begin
                        kittlight <= 8'b01000010;
                    end
                    else if (kittstep == 7) begin
                        kittlight <= 8'b10000001;
                    end
                end

                // If we're reached the last step, change direciton
                kittstep <= kittstep + 1'b1;
                if (kittstep[3] == 1'b1) begin
                    kittstep[4:0] <= 4'b0;
                    kittdirection <= ~kittdirection;
                end

            end

            // Always update the light
            output_byte <= ~kittlight[7:0];
        end
        else if (enable == 1'b0)
        begin
            counter <= counter + 1'b1;
            output_byte <= ~counter[23:16];
        end
    end

endmodule