Honored ContributorHi,
I have a question and maybe you can help me. I am writing a code in VHDL and I came across the following problem: I have a four-bit input, ranging from 0 to 9 with time, called "Hundreds" and need to concatenate it with the following string: "100011". I wonder if the following code snippet work: "100011"&hundreds; If you do not work, how do I solve this problem? Thank you
Honored ContributorWithout seeing the full code, we will have no idea. Why not try some code and compiling it?
Honored ContributorSorry... Below is the code:
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;Honored ContributorAnd whats the problem?
Honored ContributorMy question is whether it is right to do the following:
"100011"&hundreds When "Hundreds" equals "1001", the result will be: "100011"&"1001" = "1000111001" ? ThanksHonored ContributorThese kind of questions can quickly and easily be checked with a compiler and simulator (quicker than using a forum)
Yes, this is exactly how it works.Honored ContributorOk, thank you and apologize for the inconvenience.
Honored ContributorYou can try using Modelsim Altera Starter edition which is free to simulation the functional behavior of your logic.
