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ขอคำแนะนำเรื่องโค้ดจอ LCD

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.all;
USE IEEE.STD_LOGIC_ARITH.all;
USE IEEE.STD_LOGIC_UNSIGNED.all;
ENTITY LCD_Display IS

PORT(reset, clk_50Mhz : IN STD_LOGIC;
LCD_RS, LCD_E : OUT STD_LOGIC;
LCD_RW : OUT STD_LOGIC;
DATA_BUS : INOUT STD_LOGIC_VECTOR(7 DOWNTO 0));

END ENTITY LCD_Display;

ARCHITECTURE a OF LCD_Display IS
TYPE character_string IS ARRAY ( 0 TO 31 ) OF STD_LOGIC_VECTOR( 7 DOWNTO 0 );

TYPE STATE_TYPE IS (HOLD, FUNC_SET, DISPLAY_ON, MODE_SET, Print_String,
LINE2, RETURN_HOME, DROP_LCD_E, RESET1, RESET2,
RESET3, DISPLAY_OFF, DISPLAY_CLEAR);
SIGNAL state, next_command: STATE_TYPE;
SIGNAL LCD_display_string : character_string;
SIGNAL DATA_BUS_VALUE, Next_Char: STD_LOGIC_VECTOR(7 DOWNTO 0);
SIGNAL CLK_COUNT_400HZ: STD_LOGIC_VECTOR(19 DOWNTO 0);
SIGNAL CHAR_COUNT: STD_LOGIC_VECTOR(4 DOWNTO 0);
SIGNAL CLK_400HZ,LCD_RW_INT : STD_LOGIC;
SIGNAL Line1_chars, Line2_chars: STD_LOGIC_VECTOR(127 DOWNTO 0);
BEGIN

LCD_display_string <= (
-- ASCII hex values for LCD Display
-------------------------
--| ASTRON LOGIC |
--|WARRIOR CYCLONE3|
-------------------------
-- Line 1
X"20",X"20",X"20",X"46",X"46",X"54",X"20",X"20",X"38",X"2D",X"50",X"4F",X"49",X"4E",X"54",X"20",
-- Line 2
X"20",X"20",X"20",X"20",X"20",X"50",X"52",X"4F",X"47",X"52",X"41",X"4D",X"20",X"20",X"20",X"20"
);

DATA_BUS <= DATA_BUS_VALUE WHEN LCD_RW_INT = '0' ELSE "ZZZZZZZZ";
Next_Char <= LCD_display_string(CONV_INTEGER(CHAR_COUNT));
LCD_RW <= LCD_RW_INT;
PROCESS
BEGIN
WAIT UNTIL CLK_50MHZ'EVENT AND CLK_50MHZ = '1';
IF RESET = '0' THEN
CLK_COUNT_400HZ <= X"00000";
CLK_400HZ <= '0';
ELSE
IF CLK_COUNT_400HZ < X"0EA60" THEN
CLK_COUNT_400HZ <= CLK_COUNT_400HZ + 1;
ELSE
CLK_COUNT_400HZ <= X"00000";
CLK_400HZ <= NOT CLK_400HZ;
END IF;
END IF;
END PROCESS;
PROCESS (CLK_400HZ, reset)
BEGIN
IF reset = '0' THEN
state <= RESET1;
DATA_BUS_VALUE <= X"38";
next_command <= RESET2;
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '1';

ELSIF CLK_400HZ'EVENT AND CLK_400HZ = '1' THEN
CASE state IS
WHEN RESET1 =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"38";
state <= DROP_LCD_E;
next_command <= RESET2;
CHAR_COUNT <= "00000";
WHEN RESET2 =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"38";
state <= DROP_LCD_E;
next_command <= RESET3;
WHEN RESET3 =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"38";
state <= DROP_LCD_E;
next_command <= FUNC_SET;
WHEN FUNC_SET =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"38";
state <= DROP_LCD_E;
next_command <= DISPLAY_OFF;
WHEN DISPLAY_OFF =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"08";
state <= DROP_LCD_E;
next_command <= DISPLAY_CLEAR;
WHEN DISPLAY_CLEAR =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"01";
state <= DROP_LCD_E;
next_command <= DISPLAY_ON;
WHEN DISPLAY_ON =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"0C";
state <= DROP_LCD_E;
next_command <= MODE_SET;
WHEN MODE_SET =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"06";
state <= DROP_LCD_E;
next_command <= Print_String;
WHEN Print_String =>
state <= DROP_LCD_E;
LCD_E <= '1';
LCD_RS <= '1';
LCD_RW_INT <= '0';
IF Next_Char(7 DOWNTO 4) /= X"0" THEN
DATA_BUS_VALUE <= Next_Char;
ELSE
IF Next_Char(3 DOWNTO 0) >9 THEN
DATA_BUS_VALUE <= X"4" & (Next_Char(3 DOWNTO 0)-9);
ELSE
DATA_BUS_VALUE <= X"3" & Next_Char(3 DOWNTO 0);
END IF;
END IF;
state <= DROP_LCD_E;
IF (CHAR_COUNT < 31) AND (Next_Char /= X"FE") THEN
CHAR_COUNT <= CHAR_COUNT +1;
ELSE
CHAR_COUNT <= "00000";
END IF;
IF CHAR_COUNT = 15 THEN next_command <= line2;
ELSIF (CHAR_COUNT = 31) OR (Next_Char = X"FE") THEN
next_command <= return_home;
ELSE next_command <= Print_String; END IF;
WHEN LINE2 =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"C0";
state <= DROP_LCD_E;
next_command <= Print_String;
WHEN RETURN_HOME =>
LCD_E <= '1';
LCD_RS <= '0';
LCD_RW_INT <= '0';
DATA_BUS_VALUE <= X"80";
state <= DROP_LCD_E;
next_command <= Print_String;
WHEN DROP_LCD_E =>
LCD_E <= '0';
state <= HOLD;
WHEN HOLD =>
state <= next_command;
END CASE;
END IF;
END PROCESS;
END a;


อันนี้เป็นโค้ดที่สั่งให้บอร์ด แสดงข้อความค้างไว้ ถ้าเราต้องการ ให้มีหน่วงเวลา ประมาณ 5 วินาที แล้วแสดงข้อความใหม่ ต้องเพิ่มเติมโค้ดส่วนไหนบ้างครับ แนะนำทีครับ ขอบคุณครับ