display.vhd

程序用VHDL实现： 利用一秒定时测量频率 并且显示

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity display is
 port(hou10:in std_logic_vector(3 downto 0);
      hou1:in std_logic_vector(3 downto 0);
      min10:in std_logic_vector(3 downto 0);
      min1:in std_logic_vector(3 downto 0);
      sec10:in std_logic_vector(3 downto 0);
      sec1:in std_logic_vector(3 downto 0);
      clk:in std_logic;
      ledout:out std_logic_vector(6 downto 0);
      ledpt:out std_logic;
       sa,sb,sc:out std_logic);
end display;

architecture behav of display is
 signal insig:integer range 0 to 12;
 signal counter:integer range 0 to 5;
 signal ledwk: std_logic_vector(2 downto 0);
begin
 process(clk)
  begin
   if(clk'event and clk='1')then 
     if(counter=5)then
       counter<=0;
     else
       counter<=counter+1;
     end if;
   end if;
 end process;
 process(counter,clk)
 begin
  if(clk'event and clk='1')then
    if(counter=0)then 
      ledwk<="000";
      insig<=conv_integer(sec1);
      ledpt<='1';
    elsif(counter=1)then 
      ledwk<="001";
      insig<=conv_integer(sec10);
      ledpt<='0';
    elsif(counter=2)then 
      ledwk<="010";
      insig<=conv_integer(min1);
      ledpt<='1';
    elsif(counter=3)then 
      ledwk<="011";
      insig<=conv_integer(min10);
      ledpt<='0';
    elsif(counter=4)then 
      ledwk<="100";
      insig<=conv_integer(hou1);
      ledpt<='1';
    else 
      ledwk<="101";
      insig<=conv_integer(hou10);
      ledpt<='0';
    end if;
  end if;
 end process;
 process(insig)
  begin
   if(insig=0)then
    ledout<="0111111";
   elsif(insig=1)then
    ledout<="0000110";
   elsif(insig=2)then
    ledout<="1011011";
   elsif(insig=3)then
    ledout<="1001111";
   elsif(insig=4)then
    ledout<="1100110";
   elsif(insig=5)then
    ledout<="1101101";
   elsif(insig=6)then
    ledout<="1111101";
   elsif(insig=7)then
    ledout<="0000111";
   elsif(insig=8)then
    ledout<="1111111";
   elsif(insig=9)then
    ledout<="1101111";
   elsif(insig=10)then
    ledout<="0111000";
   elsif(insig=11)then
    ledout<="1000000";
   elsif(insig=12)then
    ledout<="0110110";
   end if;
 end process;
sa<=ledwk(0);
sb<=ledwk(1);
sc<=ledwk(2);
end behav;