数字逻辑与数字系统（VHDL）动态扫描数码显示器

分析

做一个动态扫描数码显示器 一共需要三个部件：

模八计数器、8选一数据选择器、7段译码器

模八计数器

Library ieee;
Use ieee.std_logic_1164.all;
Use ieee.std_logic_unsigned.all;
Use ieee.std_logic_arith;

Entity m8 is
  port(en,clr,clk:in std_logic;
         q:out std_logic_vector(2 downto 0)
       );
end m8;


architecture s_m8 of m8 is
signal qcl:std_logic_vector(2 downto 0);
begin 
   process(en,clr,clk)
        if(clr='0')then
          qcl<="000";
        elseif(clk'event and clk='1')then
          if(en='1')then
            if(qcl="111")then
               qcl<="000";
            else
               qcl<=qcl+'1';
            end if;
          end if;
        end if;
      q<=qcl;
   end process;
end s_m8;

8选一数据选择器

<span style="font-weight: normal;"><span style="font-size:10px;">Library ieee;
Use ieee.std_logic_1164.all;
Use ieee.std_logic_unsigned.all;
Use ieee.std_logic_arith;

Entity xz8 is
  port(d0,d1,d2,d3,d4,d5,d6,d7:in std_logic_vector(3 downto 0);
        sel:in std_logic_vector(2 downto 0);
         q:out std_logic_vector(3 downto 0)
      );
end xz8;

architecture s_xz8 of xz8 is
signal qc:std_logic_vector(2 downto 0);
begin
   process(d0,d1,d2,d3,d4,d5,d6,d7,sel)
      begin
      case sel is
        when "000"=>qc<=d0;
        when "001"=>qc<=d1;
        when "010"=>qc<=d2;
        when "011"=>qc<=d3;
        when "100"=>qc<=d4;
        when "101"=>qc<=d5;
        when "110"=>qc<=d6;
        when "111"=>qc<=d7;
      end case;
   end process;
end s_xz8;</span></span>

7段译码器

Library ieee;
Use ieee.std_logic_1164.all;
Use ieee.std_logic_unsigned.all;
Use ieee.std_logic_arith;

Entity ymq is
  port(d:in std_logic_vector(3 downto 0);
       f:out std_logic_vector(6 downto 0)
      );
end ymq;

architecture s_ymq of ymq is
begin
   process(d)
      begin
      case d is
         when "0000"=>f<="0111111";
         when "0001"=>f<="0000110";
         when "0010"=>f<="1011011";
         when "0011"=>f<="1001111";
         when "0100"=>f<="1100110";
         when "0101"=>f<="1101101";
         when "0110"=>f<="1111101";
         when "0111"=>f<="0100111";
         when "1000"=>f<="1111111";
         when "1001"=>f<="1101111";
         when others=>f<="XXXXXXX";
      end case;
   end process;
end s_ymq;

PS：

时间太久想不起更具体的了= =就酱暂且记录一下