8421码转格雷码LIBRARY IEEE;USE IEEE.STD_LOGIC_1164.ALL;USE IEEE.STD_LOGIC_UNSIGNED.ALL;USE IEEE.STD_LOGIC_ARITH.ALL;ENTITY B2G ISGENERIC( n:INTEGER :=4);P0RT(n orm : IN STD_LOGIC_VECTOR( n-1 DOWNTO 0);grey : OUT STD_LOGIC_VECTOR( n-1 DOWNTO 0);END B2G;ARCHITECTURE behave OF B2G ISSIGNAL temp_normal : STD_LOGIC_VECTOR( n-1 DOWNTO 0);SIGNAL temp_grey : STD_LOGIC_VECTOR( n-1 DOWNTO 0);BEGINPROCESS( norm)BEGINtemp_ normal = no rm;temp_grey( n-1) = temp _n ormal( n-1)FOR i IN n-2 DOWNTO 0 LOOPtemp_grey(i) = temp_ normal(i+1) xor temp_ normal(i);END LOOP;grey BBBBBBBBBBB=0000000;END CASE;END PROCESS;END;四人多数表决器LIBRARY IEEE;USE IEEE.STD_LOGIC_1164.ALL;ENTITY biaojueqi ISPORT(A3,A2,A1,A0:IN STD_LOGIC;Y :OUT STD_LOGIC);END biaojueqi;ARCHITECTURE behave OF biaojueqi ISSIGNAL comb :STD_LOGIC_VECTOR(3 DOWNTO 0);signal d: STD_LOGIC_VECTOR(15 DOWNTO 0);BEGINcombYYYYYY=1;END CASE;END PROCESS;END behave;