Concatenation in VHDL

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LIBRARY ieee;

USE ieee.std_logic_1164.all;

ENTITY dados_lcd IS

PORT(

clk : IN STD_LOGIC; --system clock

hundreds : IN STD_LOGIC_VECTOR(3 DOWNTO 0);

tens : IN STD_LOGIC_VECTOR(3 DOWNTO 0);

unit : IN STD_LOGIC_VECTOR(3 DOWNTO 0);

rw, rs, e : OUT STD_LOGIC; --read/write, setup/data, and enable for lcd

lcd_data : OUT STD_LOGIC_VECTOR(7 DOWNTO 0)); --data signals for lcd

END dados_lcd;

ARCHITECTURE behavioral OF dados_lcd IS

SIGNAL lcd_enable : STD_LOGIC;

SIGNAL lcd_bus : STD_LOGIC_VECTOR(9 DOWNTO 0);

SIGNAL lcd_busy : STD_LOGIC;

COMPONENT lcd_controller IS

PORT(

clk : IN STD_LOGIC; --system clock

reset_n : IN STD_LOGIC; --active low reinitializes lcd

lcd_enable : IN STD_LOGIC; --latches data into lcd controller

lcd_bus : IN STD_LOGIC_VECTOR(9 DOWNTO 0); --data and control signals

busy : OUT STD_LOGIC; --lcd controller busy/idle feedback

rw, rs, e : OUT STD_LOGIC; --read/write, setup/data, and enable for lcd

lcd_data : OUT STD_LOGIC_VECTOR(7 DOWNTO 0)); --data signals for lcd

END COMPONENT;

BEGIN

--instanciando o lcd_controller

dados: lcd_controller

PORT MAP(clk => clk,

reset_n => '1',

lcd_enable => lcd_enable,

lcd_bus => lcd_bus,

busy => lcd_busy,

rw => rw,

rs => rs,

e => e,

lcd_data => lcd_data

);

PROCESS(clk, hundreds, tens, unit)

VARIABLE char : INTEGER RANGE 0 TO 25 := 0;

BEGIN

IF(clk'EVENT AND clk = '1') THEN

IF(lcd_busy = '0' AND lcd_enable = '0') THEN

lcd_enable <= '1';

IF(char < 25) THEN

char := char + 1;

END IF;

CASE char IS

WHEN 1 => lcd_bus <= "1001000100"; --D

WHEN 2 => lcd_bus <= "1001001001"; --I

WHEN 3 => lcd_bus <= "1001010011"; --S

WHEN 4 => lcd_bus <= "1001010100"; --T

WHEN 5 => lcd_bus <= "1010110110"; --Â

WHEN 6 => lcd_bus <= "1001001110"; --N

WHEN 7 => lcd_bus <= "1001000011"; --C

WHEN 8 => lcd_bus <= "1001001001"; --I

WHEN 9 => lcd_bus <= "1001000001"; --A

WHEN 10 => lcd_bus <= "1000111010"; --:

WHEN 11 => lcd_bus <= "0011000000"; --Command (cursor primeira posição da segunda linha)

WHEN 12 => lcd_bus <= "1000100000"; --SPC

WHEN 13 => lcd_bus <= "1000100000"; --SPC

WHEN 14 => lcd_bus <= "1000100000"; --SPC

WHEN 15 => lcd_bus <= "1000100000"; --SPC

WHEN 16 => lcd_bus <= "1000100000"; --SPC

WHEN 17 => lcd_bus <= "1000100000"; --SPC

WHEN 18 => lcd_bus <= "1000100000"; --SPC

WHEN 19 => lcd_bus <= "1000100000"; --SPC

WHEN 20 => lcd_bus <= "1000100000"; --SPC

WHEN 21 => lcd_bus <= "1000100000"; --SPC

WHEN 22 => lcd_bus <= "100011"&hundreds; --centenas

WHEN 23 => lcd_bus <= "100011"&tens; --dezenas

WHEN 24 => lcd_bus <= "100011"&unit; --unidades

WHEN OTHERS => lcd_enable <= '0';

END CASE;

ELSE

lcd_enable <= '0';

END IF;

END IF;

END PROCESS;

END behavioral;