lcd.v

module textlcd_submodule(input rst,
                         input clk,
                         input[3:0] strike,
                         input[3:0] ball,
                         input[7:0] lcd_data_external,
                         output wire lcd_e,
                         output reg lcd_rs,
                         output reg lcd_rw,
                         output reg [7:0] lcd_data);
    
    always @* lcd_data = lcd_data_external;
    
    reg [2:0] state;
    parameter delay = 3'b000,
    function_set = 3'b001,
    entry_mode = 3'b010,
    disp_onoff = 3'b011,
    line1 = 3'b100,
    line2 = 3'b101,
    delay_t = 3'b110,
    clear_disp = 3'b111;
    
    integer cnt;
    integer cnt_100hz;
    reg clk_100hz;
    
    always @(posedge rst or posedge clk)
    begin
        if (rst)
        begin
            cnt_100hz = 0;	  clk_100hz = 1'b0;
        end
        else if (cnt_100hz > = 4)
        begin
            cnt_100hz = 0;	  clk_100hz = ~ clk_100hz;
        end
        else
            cnt_100hz = cnt_100hz + 1;
    end
    
    
    always @(posedge rst or posedge clk_100hz)
    begin
        if (rst)
            state = delay;
        else
        begin
            case (state)
                delay :     	    if (cnt == 70) state = function_set;
                function_set :   if (cnt == 30) state = disp_onoff;
                disp_onoff :	    if (cnt == 30) state = entry_mode;
                entry_mode :	    if (cnt == 30) state = line1;
                line1 :    	    if (cnt == 20) state  = line2;
                line2 :    	    if (cnt == 20) state  = delay_t;
                delay_t:    	    if (cnt == 400) state = clear_disp;
                clear_disp :	    if (cnt == 200) state = line1;
                default : state          = delay;
            endcase
        end
    end
    
    always @(posedge rst or posedge clk_100hz)
    begin
        if (rst)
            cnt = 0;
        else
        begin
            case (state)
                delay :
                if (cnt > = 70) cnt = 0;    else cnt = cnt + 1;
                function_set :
                if (cnt > = 30) cnt = 0;    else cnt = cnt + 1;
                disp_onoff :
                if (cnt > = 30) cnt = 0;    else cnt = cnt + 1;
                entry_mode :
                if (cnt > = 30) cnt = 0;    else cnt = cnt + 1;
                line1 :
                if (cnt > = 20) cnt = 0;    else cnt = cnt + 1;
                line2 :
                if (cnt > = 20) cnt = 0;    else cnt = cnt + 1;
                delay_t :
                if (cnt > = 400) cnt = 0;   else cnt = cnt + 1;
                clear_disp :
                if (cnt >     = 200) cnt     = 0;   else cnt     = cnt + 1;
                default : cnt = 0;
            endcase
        end
    end
    
    
    always @(posedge rst or posedge clk_100hz)
    begin
        if (rst)
        begin
            lcd_rs   = 1'b1;
            lcd_rw   = 1'b1;
            lcd_data = 8'b00000000;
        end
        else
        begin
            case (state)
                function_set :
                begin
                    lcd_rs = 1'b0;    lcd_rw = 1'b0;    lcd_data = 8'b00111100;
                end
                disp_onoff :
                begin
                    lcd_rs = 1'b0;    lcd_rw = 1'b0;    lcd_data = 8'b00001100;
                end
                entry_mode :
                begin
                    lcd_rs = 1'b0;    lcd_rw = 1'b0;    lcd_data = 8'b00000110;
                end
                
                line1 :
                begin
                    lcd_rw = 1'b0;
                    
                    case (cnt)
                        0 :  begin
                            lcd_rs = 1'b0;  lcd_data = 8'b10000000;
                        end
                        1 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00110000 | strike; // S
                        end
                        2 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b01010011; // S
                        end
                        3 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00100000; // space
                        end
                        4 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00110000 | ball; // B
                        end
                        5 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b01000010; // B
                        end
                        6 : begin
                            lcd_rs = 1'b1;  lcd_data = 8'b00100000;
                        end
                        7 : begin
                            lcd_rs = 1'b1;  lcd_data = 8'b00100000;
                        end
                        default : begin
                            lcd_rs = 1'b1;  lcd_data = 8'b00100000;
                        end
                    endcase
                end
                
                line2 :
                begin
                    lcd_rw = 1'b0;
                    
                    case (cnt)
                        0 : begin
                            lcd_rs = 1'b0;  lcd_data = 8'b11000000;
                        end
                        9 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00100000;
                        end
                        10 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00100000;
                        end
                        11 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00100000;
                        end
                        12 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00100000;
                        end
                        13 : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00100000;
                        end
                        default : begin
                            lcd_rs = 1'b1;   lcd_data = 8'b00100000;
                        end
                    endcase
                end
                
                delay_t :
                begin
                    lcd_rs = 1'b0; lcd_rw = 1'b0;   lcd_data = 8'b00000010;
                end
                
                clear_disp :
                begin
                    lcd_rs = 1'b0; lcd_rw = 1'b0;   lcd_data = 8'b00000001;
                end
                
                default :
                begin
                    lcd_rs = 1'b1; lcd_rw = 1'b1; lcd_data = 8'b00000000;
                end
            endcase
        end
    end
    
    assign lcd_e = clk_100hz;
    
endmodule