扫描 (2).txt

vhdl 关于键盘扫描的程序 。。。。 很有用的 。。。。。。也很好

library altera;
use altera.maxplus2.all;
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;


entity keyctrl is
port( clk,reset:in std_logic;
      vv:in std_logic_vector(3 downto 0);               --vv1-vv4
      vh:inout std_logic_vector(3 downto 0);            --vh1-vh4
      show:out std_logic_vector(6 downto 0);            --led(0)-led(6)
      row:out std_logic;
      d_in:in std_logic;
      d_out:out std_logic);                             --选择一个数码管
end keyctrl;

architecture behav of keyctrl is
signal showout:std_logic_vector(6 downto 0);
signal keydown:std_logic_vector(7 downto 0);
signal q:std_logic_vector(21 downto 0);
signal clk1:std_logic;
begin
row<='1';
p0: process(clk)
    begin
    if clk'event and clk='1' then
    q<=q+1;
    end if;
    end process p0;
    clk1 <= q(7);
p1: process(clk)
variable counter:integer range 0 to 3;                   --键盘扫描计数
begin
    if reset='1'then counter:=0;
    elsif clk'event and clk='1'then
    if counter=3 then counter:=0;
    else counter:=counter+1;
    end if;
    case counter is
    when 0=> vh<="1110";                            --选中vh1
    when 1=> vh<="1101";                            --选中vh2
    when 2=> vh<="1011";                            --选中vh3
    when 3=> vh<="0111";                            --选中vh4
    end case;
    keydown<=vh&vv;
    case keydown is
              when "11101110"=>showout<="0111111";  --0 vh1&vv1
              when "11101101"=>showout<="0000110";  --1 vh1&vv2
              when "11101011"=>showout<="1011011";  --2 vh1&vv3
              when "11100111"=>showout<="1001111";  --3 vh1&vv4
              when "11011110"=>showout<="1100110";  --4 vh2&vv1
              when "11011101"=>showout<="1101101";  --5 vh2&vv2
              when "11011011"=>showout<="1111101";  --6 vh2&vv3
              when "11010111"=>showout<="0000111";  --7 vh2&vv4
              when "10111110"=>showout<="1111111";  --8 vh3&vv1
              when "10111101"=>showout<="1101111";  --9 vh3&vv2
              when "10111011"=>showout<="1110111";  --A vh3&vv3
              when "10110111"=>showout<="1111100";  --B vh3&vv4
              when "01111110"=>showout<="0111001";  --C vh4&vv1
              when "01111101"=>showout<="1011110";  --D vh4&vv2
              when "01111011"=>showout<="1111001";  --E vh4&vv3
              when "01110111"=>showout<="1110001";  --F vh4&vv4
              when others=>null;
end case;
end if;
end process;
show<=showout;
end behav;

architecture a of keyctrl IS
signal  vcc, inv_d : std_logic ;
signal  q0, q1  : std_logic ;
signal  d1, d0  : std_logic ;

begin
    vcc <= '1' ;
    inv_d <= not d_in ;
    dff1 : dff port map (d =>vcc , q => q0 , clk => clk,   clrn =>inv_d , prn => vcc);
    dff2 : dff port map (d =>vcc , q => q1,  clk => clk,   clrn => q0 ,   prn => vcc);

process (clk)
begin
 if clk'event and clk='1' then
    d0 <= not q1; 
    d1 <= d0;
 end if ;
end process ;
d_out <= not (d1 and not d0);
end a;