VHDL TB for 3 bit bcd to binary - vhdl

Question

I've got a problem with my test bench for 3 bit BCD to binary decoder.
Inputs are fine but output is UUUUUU.....
No idea how to resolve it. Should I assign output somehow?
I'm using ISE to simulate code.
I have been trying to apply method I have been using in behavioral model but its not accepting it.
-- TestBench Template
LIBRARY ieee;
USE ieee.std_logic_1164.ALL;
USE ieee.numeric_std.ALL;
ENTITY testbench IS
END testbench;
ARCHITECTURE behavior OF testbench IS
COMPONENT bcd_2_bin
PORT(
bcd_in_0 : IN std_logic_vector(3 downto 0);
bcd_in_10 : IN std_logic_vector(3 downto 0);
bcd_in_100 : IN std_logic_vector(3 downto 0);
bin_out : OUT std_logic_vector(9 downto 0)
);
END COMPONENT;
signal bcd_in_0 : std_logic_vector(3 downto 0) := (others => '0');
signal bcd_in_10 : std_logic_vector(3 downto 0) := (others => '0');
signal bcd_in_100 : std_logic_vector(3 downto 0) := (others => '0');
signal bin_out : std_logic_vector(9 downto 0);
BEGIN
-- Instantiate the Unit Under Test (UUT)
uut: bcd_2_bin PORT MAP (
bcd_in_0 => bcd_in_0,
bcd_in_10 => bcd_in_10,
bcd_in_100 => bcd_in_100,
bin_out => bin_out
);
-- Stimulus process
stim_proc: process
begin
bcd_in_0 <= x"0"; bcd_in_10 <= x"1"; bcd_in_100 <= x"2";
wait for 100 ns;
bcd_in_0 <= x"9"; bcd_in_10 <= x"9"; bcd_in_100 <= x"9";
wait for 100 ns;
bcd_in_0 <= x"8"; bcd_in_10 <= x"2"; bcd_in_100 <= x"4";
wait;
end process;
END;

Answer 1

There is no problem in your testbench. I checked with the following dummy UUT,
ibrary ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
entity bcd_2_bin is
port (
bcd_in_0 : IN std_logic_vector(3 downto 0);
bcd_in_10 : IN std_logic_vector(3 downto 0);
bcd_in_100 : IN std_logic_vector(3 downto 0);
bin_out : OUT std_logic_vector(9 downto 0)
);
end bcd_2_bin;
architecture dummy of bcd_2_bin is
begin
bin_out(3 downto 0) <= bcd_in_0;
bin_out(7 downto 4) <= bcd_in_10;
bin_out(9 downto 8) <= bcd_in_100(1 downto 0);
end dummy;
and simulated your testbench successfully without any changes.
Look inside your UUT source to find the problem. Check also for errors or warnings during compilation.