cnt0.vhd

包含了电子时钟的主要功能,输入CLK为1KHZ,输出为动态扫描8段CLD显示.有闹铃,正点报时,时间调整.调整时能够闪烁显示.本时钟为24小时制.课程设计优秀通过.运行平台:MAX+PLUS2.

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;

entity cnt0 is
port(clk: in std_logic;
nao: in std_logic;
adj: in std_logic;
adjust:in std_logic_vector(4 downto 0);
ringnao,ringzheng:out std_logic;
qsl:out std_logic_vector(3 downto 0);
qsh:out std_logic_vector(3 downto 0);
qml:out std_logic_vector(3 downto 0);
qmh:out std_logic_vector(3 downto 0);
qhl:out std_logic_vector(3 downto 0);
qhh:out std_logic_vector(3 downto 0));
end cnt0;

architecture a of cnt0 is
signal inter_clk:std_logic;
signal tqsl,tqsh,tqml,tqmh,tqhh,tqhl,naotqsl,naotqsh,naotqml,naotqmh,naotqhh,
       naotqhl:integer range 0 to 10;
signal tqh,naotqh:integer range 0 to 25;
begin
inter_clk<= clk or adj;
tqhl<=   tqh when tqh>=0 and tqh<10 else
      tqh-10 when tqh>=10 and tqh<20 else
      tqh-20 when tqh>=20 and tqh<24 else
      0;
tqhh<=   0 when tqh>=0 and tqh<10 else
         1 when tqh>=10 and tqh<20 else
         2 when tqh>=20 and tqh<24 else
         0;
naotqhl<=   tqh when naotqh>=0 and naotqh<10 else
      naotqh-10 when naotqh>=10 and naotqh<20 else
      naotqh-20 when naotqh>=20 and naotqh<24 else
      0;
naotqhh<=   0 when naotqh>=0 and naotqh<10 else
      1 when naotqh>=10 and naotqh<20 else
      2 when naotqh>=20 and naotqh<24 else
      0;


process(inter_clk)
begin
if(inter_clk'event and inter_clk='1' ) then
   if (nao='1') then
--sec
      if (adj='0' and tqsl=9)or(adjust="00001"and tqsl=9)then tqsl<=0;
              elsif (adj='0' and tqsl/=9)or (adjust="00001" and tqsl/=9) then tqsl<=tqsl+1;
              else tqsl<=tqsl;
       end if;
       if(adj='0' and tqsh=5 and tqsl=9)or(adjust(1)='1' and tqsh=5) then 
    tqsh<=0;
         elsif(adj='0' and tqsh/=5 and tqsl=9)or(adjust(1)='1' and tqsh/=5) then 
            tqsh<=tqsh+1;
               else tqsh<=tqsh;
       end if;
--min;
       if (adj='0' and tqml=9 and tqsh=5 and tqsl=9)or (adjust(2)='1' and tqml=9)then
            tqml<=0;
       elsif (adj='0' and tqml/=9 and tqsh=5 and tqsl=9)or(adjust(2)='1' and tqml/=9)then
            tqml<=tqml+1;
         else tqml<=tqml;
       end if;
       if(adj='0' and tqmh=5 and tqml=9 and tqsh=5 and tqsl=9)or(adjust(3)='1' and tqmh=5)then 
            tqmh<=0;
       elsif (adj='0' and tqmh/=5 and tqml=9 and tqsh=5 and tqsl=9)or (adjust(3)='1'and tqmh/=5)then
            tqmh<=tqmh+1;
         else tqmh<=tqmh;
        end if;
--hour
        if(adj='0' and tqh=23 and tqmh=5 and tqml=9 and tqsh=5 and tqsl=9)or(adjust(4)='1' and tqh=23)
            then    tqh<=0;
         elsif(adj='0' and tqh/=23 and tqmh=5 and tqml=9 and tqsh=5 and tqsl=9)or(adjust(4)='1' and tqh/=23)
            then tqh<=tqh+1;
        else tqh<=tqh;
qsl<=conv_std_logic_vector(tqsl,4);
qsh<=conv_std_logic_vector(tqsh,4);
qml<=conv_std_logic_vector(tqml,4);
qmh<=conv_std_logic_vector(tqmh,4);
qhl<=conv_std_logic_vector(tqhl,4);
qhh<=conv_std_logic_vector(tqhh,4);
         end if;
else
--sec
        if (adjust="00001"and naotqsl=9)then naotqsl<=0;
          elsif(adjust="00001" and naotqsl/=9) then naotqsl<=naotqsl+1;
             else naotqsl<=naotqsl;
         end if;
         if (adjust(1)='1' and naotqsh=5) then  naotqsh<=0;
            elsif (adjust(1)='1' and naotqsh/=5) then 
               naotqsh<=naotqsh+1;
                 else naotqsh<=naotqsh;
          end if;
--min;
          if (adjust(2)='1' and naotqml=9)then
                naotqml<=0;
             elsif (adjust(2)='1' and naotqml/=9)then
               naotqml<=naotqml+1;
              else naotqml<=naotqml;
           end if;
           if(adjust(3)='1' and naotqmh=5)then 
                naotqmh<=0;
               elsif (adjust(3)='1'and naotqmh/=5)then
                  naotqmh<=naotqmh+1;
              else naotqmh<=naotqmh;
            end if;
--hour
            if(adjust(4)='1' and naotqh=23)
                  then    naotqh<=0;
                     elsif(adjust(4)='1' and naotqh/=23)
                          then naotqh<=tqh+1;
                     else naotqh<=naotqh;
            end if;
qsl<=conv_std_logic_vector(naotqsl,4);
qsh<=conv_std_logic_vector(naotqsh,4);
qml<=conv_std_logic_vector(naotqml,4);
qmh<=conv_std_logic_vector(naotqmh,4);
qhl<=conv_std_logic_vector(naotqhl,4);
qhh<=conv_std_logic_vector(naotqhh,4);
    end if;
end if;
end process;

process(clk)
begin
if (tqsl=naotqsl and tqsh=naotqsh and tqml=naotqml and tqmh=naotqmh and tqh=naotqh) then
ringnao<='1';
end if;
if (tqmh=5 and tqml=9 and tqsh=5 and tqsl=9) then
ringzheng<='1';
end if;
end process;
end ;