tone.vhd

利用VHDL编写的电子琴发生器

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY Tone IS
    PORT ( Index :  IN STD_LOGIC_VECTOR(7 DOWNTO 0);
           HORL  :  IN STD_LOGIC; 
           CODE  : OUT INTEGER RANGE 0 TO 15;
           NUME  : OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
           HIGH  : OUT STD_LOGIC; 
           Tone  : OUT INTEGER RANGE 0 TO 16#7FF#  );
END;
ARCHITECTURE one OF Tone IS
   SIGNAL KLK :  STD_LOGIC_VECTOR(1 DOWNTO 0);
BEGIN
   PROCESS(HORL)
     BEGIN
        IF HORL'EVENT AND HORL = '1' THEN      KLK <= KLK + 1;   
                  END IF;
          NUME <= '0'&'0'& KLK; 
   END PROCESS;     
    Search : PROCESS(Index)
    BEGIN
        IF KLK = "00" THEN
        CASE Index IS       -- 译码电路，查表方式，控制音调的预置数
            WHEN "00000001"  => TONE <= 773;  CODE <= 1; HIGH <= '0';  
            WHEN "00000010"  => TONE <= 912;  CODE <= 2; HIGH <= '0';  
            WHEN "00000100"  => TONE <= 1036; CODE <= 3; HIGH <= '0'; 
            WHEN "00001000"  => TONE <= 1116; CODE <= 4; HIGH <= '0'; 
            WHEN "00010000"  => TONE <= 1197; CODE <= 5; HIGH <= '0';  
            WHEN "00100000"  => TONE <= 1290; CODE <= 6; HIGH <= '0';  
            WHEN "01000000"  => TONE <= 1372; CODE <= 7; HIGH <= '0';
            WHEN "10000000"  => TONE <= 1410; CODE <= 8; HIGH <= '0';
            WHEN   OTHERS   => TONE <= 2047;  CODE <= 0; HIGH <= '0';  
        END CASE;
        ELSIF KLK = "01" THEN
        CASE Index IS       -- 译码电路，查表方式，控制音调的预置数
            WHEN "00000001"  => TONE <= 1410;  CODE <= 1; HIGH <= '1';  
            WHEN "00000010"  => TONE <= 1490;  CODE <= 2; HIGH <= '1'; 
            WHEN "00000100"  => TONE <= 1560;  CODE <= 3; HIGH <= '1'; 
            WHEN "00001000"  => TONE <= 1600;  CODE <= 4; HIGH <= '1';  
            WHEN "00010000"  => TONE <= 1622;  CODE <= 5; HIGH <= '1';  
            WHEN "00100000"  => TONE <= 1650;  CODE <= 6; HIGH <= '1';  
            WHEN "01000000"  => TONE <= 1690;  CODE <= 7; HIGH <= '1';
            WHEN "10000000"  => TONE <= 1730;  CODE <= 8; HIGH <= '1';  
            WHEN   OTHERS   => TONE <= 2047;  CODE <= 0; HIGH <= '1'; 
        END CASE;
       ELSIF KLK = "10" THEN
        CASE Index IS       -- 译码电路，查表方式，控制音调的预置数
            WHEN "00000001"  => TONE <= 1730;  CODE <= 1; HIGH <= '1'; 
            WHEN "00000010"  => TONE <= 1750;  CODE <= 2; HIGH <= '1'; 
            WHEN "00000100"  => TONE <= 1770;  CODE <= 3; HIGH <= '1'; 
            WHEN "00001000"  => TONE <= 1790;  CODE <= 4; HIGH <= '1';  
            WHEN "00010000"  => TONE <= 1815;  CODE <= 5; HIGH <= '1';  
            WHEN "00100000"  => TONE <= 1830;  CODE <= 6; HIGH <= '1';  
            WHEN "01000000"  => TONE <= 1930;  CODE <= 7; HIGH <= '1';
            WHEN "10000000"  => TONE <= 1945;  CODE <= 8; HIGH <= '1';  
            WHEN   OTHERS   => TONE <= 2047;  CODE <= 0; HIGH <= '1'; 
        END CASE;

        ELSE
            CASE Index IS       -- 译码电路，查表方式，控制音调的预置数
            WHEN "00000001"  => TONE <= 100;  CODE <= 1; HIGH <= '1';  
            WHEN "00000010"  => TONE <= 200;  CODE <= 2; HIGH <= '1'; 
            WHEN "00000100"  => TONE <= 300;  CODE <= 3; HIGH <= '1'; 
            WHEN "00001000"  => TONE <= 400;  CODE <= 4; HIGH <= '1';  
            WHEN "00010000"  => TONE <= 500;  CODE <= 5; HIGH <= '1';  
            WHEN "00100000"  => TONE <= 600;  CODE <= 6; HIGH <= '1';  
            WHEN "01000000"  => TONE <= 700;  CODE <= 7; HIGH <= '1';
            WHEN "10000000"  => TONE <= 800;  CODE <= 8; HIGH <= '1';  
            WHEN   OTHERS   => TONE <= 2047; CODE <= 0; HIGH <= '1'; 
        END CASE;
      END IF;
    END PROCESS;
END;