k thanks ....
i do what u say...
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.numeric_bit.all;
use ieee.numeric_std;
--use ieee.std_logic_arith.all;
entity adc is
port(clk:in std_logic;a:in std_logic_vector(15 downto 0);vout
ut real);
end adc;
architecture a_body of adc is
begin
process(clk)
begin
if(clk='1')then
Vout <= (3.3 * ((real((to_integer(unsigned(a)))) / 65535.0)));
end if;
end process;
end a_body;
but still i have one problem......
** Error: D:/project files/wsn and prng/foldedtree.vhd(19): Illegal type conversion from ieee.std_logic_1164.std_logic_vector to ieee.numeric_bit.unsigned (array element type difference).
** Error: D:/project files/wsn and prng/foldedtree.vhd(23): VHDL Compiler exiting