tonetaba.vhd

用VHDL语言写的

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY ToneTaba IS
	PORT ( Index : IN STD_LOGIC_VECTOR (3 DOWNTO 0);
			CODE : OUT STD_LOGIC_VECTOR (3 DOWNTO 0) ;
			HIGH : OUT STD_LOGIC;
			Tone : OUT STD_LOGIC_VECTOR (10 DOWNTO 0) );
			END;
	ARCHITECTURE one OF ToneTaba IS
	BEGIN
		Search : PROCESS (Index)
		BEGIN
			CASE Index IS
		WHEN "0000" => Tone<="11111111111" ; CODE<="0000";HIGH <='0';
		WHEN "0001" => Tone<="01100000101" ; CODE<="0001";HIGH <='0';
		WHEN "0010" => Tone<="01110010000" ; CODE<="0010";HIGH <='0';
		WHEN "1011" => Tone<="10000001100" ; CODE<="0011";HIGH <='0';
		WHEN "0101" => Tone<="10010101101" ; CODE<="0101";HIGH <='0';
		WHEN "0110" => Tone<="10100001010" ; CODE<="0110";HIGH <='0';
		WHEN "0111" => Tone<="10101011100" ; CODE<="0111";HIGH <='0';
		WHEN "1000" => Tone<="10110000010" ; CODE<="0001";HIGH <='1';
		WHEN "1001" => Tone<="10111001000" ; CODE<="0010";HIGH <='1';
		WHEN "1010" => Tone<="11000000110" ; CODE<="0011";HIGH <='1';
		WHEN "1100" => Tone<="11001010110" ; CODE<="0101";HIGH <='1';
		WHEN "1101" => Tone<="11010000100" ; CODE<="0110";HIGH <='1';
		WHEN "1111" => Tone<="11011000000" ; CODE<="0001";HIGH <='1';
		WHEN OTHERS => NULL;
		END CASE;
		END PROCESS;
	END;