D4C

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_unsigned.all;

entity KADAI14 is
port ( CLK, RESET : in std_logic;
Z : out std_logic_vector(3 downto 0));
end KADAI14;


architecture RTL of KADAI14 is
signal DEC : std_logic;
signal COUNT : std_logic_vector(3 downto 0);
begin
process( COUNT, RESET, DEC ) begin
if( COUNT = "0000" ) then
DEC <= '0';
elsif( RESET='1' ) then
DEC <= '0';
elsif( COUNT="1111" ) then
DEC <= '1';
elsif( DEC='1' and COUNT="1010" ) then
DEC <= '0';
end if;
end process;

process( CLK, RESET, DEC ) begin
if( RESET = '1' ) then
COUNT <= "0000";
elsif( CLK'event and CLK='0' ) then
if ( DEC='1' ) then
COUNT <= COUNT - 1;
else
COUNT <= COUNT + 1;
end if;
end if;
end process;

Z <= COUNT;
end RTL;

あ

無事　遺体を手にしてくれ。

理解した