PLEASE Help about Basic LED Blink

[Altera_Forum]

Hi, I'm beginner in VHDL, trying to get a true simulation result.  

 ------------THIS'S THE CODE--------- library IEEE; use IEEE.STD_LOGIC_1164.ALL; use IEEE.STD_LOGIC_ARITH.ALL; use IEEE.STD_LOGIC_UNSIGNED.ALL;   entity ensonled is port (   CLK_50MHz: in std_logic; myLED: out std_logic ); end ensonled;   architecture ensonled of ensonled is   signal counter:integer range 0 to 24999999; signal CLK_1Hz:std_logic :='0'; begin     prescaler: process(CLK_50MHz) begin    if rising_edge(CLK_50MHz) then   if counter<25000000 then   counter<=counter+1;  else   CLK_1Hz <= not CLK_1Hz;   counter <= 0;  end if;   myLED<=CLK_1Hz;  end if;   end process prescaler;   end ensonled; ---------------------  THIS'S THE TEST BENCH CODE-------------   LIBRARY ieee;  USE ieee.std_logic_1164.all;    ENTITY ensonled_vhd_tst IS END ensonled_vhd_tst; ARCHITECTURE ensonled_arch OF ensonled_vhd_tst IS -- constants  -- signals  SIGNAL CLK_50MHz : STD_LOGIC; SIGNAL myLED : STD_LOGIC; COMPONENT ensonled  PORT (  CLK_50MHz : IN STD_LOGIC;  myLED : OUT STD_LOGIC  ); END COMPONENT; BEGIN  i1 : ensonled  PORT MAP ( -- list connections between master ports and signals  CLK_50MHz => CLK_50MHz,  myLED => myLED  );   --CLK_50MHz <= not CLK_50MHz after 20 ns/2; clk_gen_proc : process begin  if CLK_50MHz /= '1' then CLK_50MHz <= '1';  else CLK_50MHz <= '0';  end if;  wait for 20 ns;   end process;       END ensonled_arch; -----------------------------------  In simulation, I always getting 'myLED' as 0 after first rising edge of Clock. And additionally, for one time, I got a result like I desired, but whenever i tried it out over again, failed. Never changed the code, it was same. But it doesn't give a damn any more. Why? Please help me. https://alteraforum.com/forum/attachment.php?attachmentid=14932&stc=1  https://alteraforum.com/forum/attachment.php?attachmentid=14932&stc=1 https://alteraforum.com/forum/attachment.php?attachmentid=14932&stc=1

[Altera_Forum]

counter is always going to be less than 25000000 because you set its max range to 24999999.

[Altera_Forum]

ahh Thanks, though i've changed it, unfortunately giving same result:( what's wrong?

[Altera_Forum]

how long are you running the simulation for? 

You need to run it for more than 500 ms for myLED to go high.