乐曲演奏广泛用于自动答录装置、手机铃声、集团电话、及智能仪器仪表设备。实现方法有许多种,随着FPGA集成度的提高,价格下降,EDA设计工具更新换代,功能日益普及与流行,使这种方案的应用越来越多。如今的数字逻辑设计者面临日益缩短的上市时间的压力,不得不进行上万门的设计,同时设计者不允许以牺牲硅的效率达到保持结构的独特性。使用现今的EDA软件工具来应付这些问题,并不是一件简单的事情。FPGA预装了很多已构造好的参数

END ENTITY Songer;

ARCHITECTURE one OF Songer IS

COMPONENT NoteTabs

PORT (clk: IN STD_LOGIC;

ToneIndex: OUT STD_LOGIC_VECTOR (3 DOWNTO 0));

END COMPONENT;

COMPONENT ToneTaba

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 COMPONENT;

COMPONENT Speakera

PORT (clk: IN STD_LOGIC;

Tone: OUT STD_LOGIC_VECTOR (10 DOWNTO 0);

SpkS: out STD_LOGIC);

END COMPONENT;

SIGNAL Tone: STD_LOGIC_VECTOR (10 DOWNTO 0);

SIGNAL ToneIndex: STD_LOGIC_VECTOR (3 DOWNTO 0);

BEGIN

u1: NoteTabs PORT MAP(clk=>CLK8HZ,ToneIndex=>ToneIndex);

u2:ToneTabaPORTMAP(Index=>ToneIndex,Tone=>Tone,CODE=>CODE1,HIGH=>HIGH

1);

u3:SpeakeraPORTMAP(clk=>CLK12MHZ,Tone=>TONE,SpkS=>SPKOUT);