1.Topclock（元件例化 頂層文件）
Library ieee;
Use ieee.std_logic_1164.all;
Use ieee.std_logic_arith.all;
Use ieee.std_logic_unsigned.all;
Entity topclock is
Port(clk,clr,en,m1,h1:in std_logic;
alarm:out std_logic;
secs,secg,mins,ming,hours,hourg:buffer std_logic_vector(3 downto 0));
End;
2.秒模塊程序
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity SECOND is
port(clk,clr:in std_logic;
sec1,sec0:out std_logic_vector(3 downto 0);
co:out std_logic);
end SECOND;
architecture SEC of SECOND is
begin
process(clk,clr)
variable cnt1,cnt0:std_logic_vector(3 downto 0);
begin
if clr='1' then
cnt1:="0000";
cnt0:="0000";
elsif clk'event and clk='1' then
if cnt1="0101" and cnt0="1000" then
coa);
u2:min1 port map(clr=>clr,alarm=>alarm,
mins=>mins,ming=>ming,clkm=>b,enmin=>c);
u3:hour1 port map(clr=>clr,
hours=>hours,hourg=>hourg,clkh=>d);
u4:madapt port map(en=>en,m1=>m1,clk=>clk,secin=>a,minset=>b);
u5:hadapt port map(en=>en,h1=>h1,clk=>clk,minin=>c,hourset=>d);
end;