encod4_2.vhd

来自「VHDL子程序集,包括各种例程资料以及源码.」· VHDL 代码 · 共 25 行

--************************************
--*  4 To 2 Encoder (WHEN ... ELSE)  *
--*        Filename : ENCOD4_2       *
--************************************
 
library IEEE;
use IEEE.std_logic_1164.all;

entity ENCOD4_2 is
    port (
          I: in STD_LOGIC_VECTOR (3 downto 0);
          A: out STD_LOGIC_VECTOR(1 downto 0)
         );
end ENCOD4_2;

architecture ENCOD4_2_arch of ENCOD4_2 is
       
begin
    A <= "00" when I = "0001" else
         "01" when I = "0010" else
         "10" when I = "0100" else
         "11" when I = "1000" else
         "ZZ";     
end ENCOD4_2_arch;