------------------------------------------------------------  test RS232: echo
--
--  Program odsy砤 z powrotem znaki kt髍e otrzyma ze z砤cza RS232 (echo).
------------------------------------------------------------------------------ 
library IEEE;
use IEEE.std_logic_1164.all;

entity  echo is
port (
       rxd: in std_logic;                                   --  odbi髍 z RS232
       txd: out std_logic                            --  nadawanie przez RS232
     );
end echo ;

architecture echo_arch of echo  is  ------------------------------------------
begin
  txd <= rxd;
end echo_arch;