key_boar_in.vhd

自定义编码的红外发射器

LIBRARY  IEEE;
USE  IEEE.STD_LOGIC_1164.ALL;
USE  IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY  key_boar_in  IS
PORT        (clk_key,reset: IN STD_LOGIC;
             key_in: in STD_LOGIC_VECTOR(12 DOWNTO 1);
             key_out: out STD_LOGIC_VECTOR(12 DOWNTO 1) ;
             ready: out std_logic
             );
END  ENTITY key_boar_in;
ARCHITECTURE arc of key_boar_in  IS
signal  count: STD_LOGIC_VECTOR(2 DOWNTO 0);
signal  key_data1, key_data2,key_data3:  std_logic_vector(12 downto 1);
 signal clk_drv: std_logic;
BEGIN

aa:PROCESS(clk_key,reset,key_in,count,key_data1,key_data2,key_data3) --- eliminate jitter
   BEGIN 
    IF  reset='1'   THEN 
        key_data1<="000000000000"; 
        key_data2<="000000000000";
        key_data3<="000000000000";
     else 
         if clk_key'event and clk_key='0' then  --- 3 times dectec key board
            case count is
               when "001" => key_data1<=key_in;            
               when "011" => key_data2<=key_in;
               when "101" => key_data3<=key_in;
               when others  =>null;                        
            end case;
         end if;
     end if;
    end process aa;

bb: process(clk_key, key_data1,key_in,count,key_data2,key_data3)
    begin
    
    if clk_key'event and clk_key='0' then
        if ( count="111"  and key_in /= "111111111111" ) then
           if  key_data1 = key_data3 and key_data2=key_data3 then
           key_out<=key_data2; 
           ready<='1';
           end if;
        else
           key_out<="000000000000" ;  
           ready<='0';   
        end if;
    end if;
   end process bb;

cc: process (clk_key ,count,reset)
     begin
     if reset='1' then
        count<="000";
      else 
        if clk_key'event and clk_key='1' then
         count<=count+1;
         end if;
      end if; 
   end process cc;



end arc;