notetabs.vhd

来自「乐曲硬件演奏电路设计的全部VHDL代码」· VHDL 代码 · 共 23 行

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY NoteTabs IS
    PORT ( clk    : IN STD_LOGIC;
        ToneIndex : OUT STD_LOGIC_VECTOR (3 DOWNTO 0) );
END;
ARCHITECTURE one OF NoteTabs IS
COMPONENT MUSIC                --音符数据ROM
 PORT(address : IN STD_LOGIC_VECTOR (7 DOWNTO 0);
	  inclock : IN STD_LOGIC ;
	        q : OUT STD_LOGIC_VECTOR (3 DOWNTO 0));
END COMPONENT;
    SIGNAL Counter :  STD_LOGIC_VECTOR (7 DOWNTO 0);
BEGIN
    CNT8 : PROCESS(clk, Counter)
    BEGIN
        IF Counter=138 THEN  Counter <= "00000000";
        ELSIF (clk'EVENT AND clk = '1') THEN Counter <= Counter+1; END IF;
    END PROCESS;
 u1 : MUSIC PORT MAP(address=>Counter , q=>ToneIndex, inclock=>clk);
 END;