1、LIBRARY IEEE;USE IEEE.STD_LOG诔罨租磊IC_1164.ALL;USE IEEE.STD_LOGIC_UNSIGNED.ALL;E绿覆冗猩NTITY speaker IS PORT(clk:IN STD_LOGIC; tone:IN STD_LOGIC_VECTOR (11 DOWNTO 0); spk:OUT STD_LOGIC);END ENTITY speaker;ARCHITECTURE one OF speaker IS SIGNAL preclk:STD_LOGIC; SIGNAL fullspk:STD_LOGIC; BEGIN --------------------- divclk:PROCESS(clk) VARIABLE Count8:STD_LOGIC_VECTOR (3 DOWNTO 0); BEGIN IF (clk'EVENT AND clk='1') THEN IF Count8>7 THEN preclk<=NOT preclk;Count8:="0000"; ELSE Count8:=Count8+1; END IF; END IF; END PROCESS divclk; ---------------------- genspk:PROCESS(preclk,tone) VARIABLE Count12:STD_LOGIC_VECTOR(11 DOWNTO 0); BEGIN IF (preclk'EVENT AND preclk='1') THEN IF Count12=16#FFF# THEN Count12:=tone;fullspk<='1'; ELSE Count12:=Count12+1;fullspk<='0'; END IF; END IF; END PROCESS genspk; ---------------------- delayspk:PROCESS (fullspk) VARIABLE Count2:STD_LOGIC; BEGIN IF (fullspk'EVENT AND fullspk='1') THEN Count2:=NOT Count2; IF Count2='1' THEN spk <='1'; ELSE spk<='0'; END IF; END IF; END PROCESS delayspk;END ARCHITECTURE one;
3、说明：tone即是分频系数spk既是产生的信号
