程序如下： LIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL; ENTITY AD IS PORT( D : IN STD_LOGIC_VECTOR(7 DOWNTO 0); CLK ,EOC : IN STD_LOGIC; Q : INOUT STD_LOGIC_VECTOR(7 DOWNTO 0); LOCK1, ALE, START ,OE, ADDA : OUT STD_LOGIC ; E : OUT STD_LOGIC_VECTOR(4 DOWNTO 0); LED7S1 : OUT STD_LOGIC_VECTOR(6 DOWNTO 0); LED7S2 : OUT STD_LOGIC_VECTOR(6 DOWNTO 0) ); END AD; ARCHITECTURE one OF AD IS TYPE states IS (st0,st1,st2,st3,st4,st5,st6); SIGNAL current_state,next_state: states :=st0; SIGNAL REGL : STD_LOGIC_VECTOR(7 DOWNTO 0); SIGNAL LOCK : STD_LOGIC; BEGIN ADDA<='1'; LOCK1<=LOCK; PRO: PROCESS(current_state,EOC) BEGIN CASE current_state IS WHEN st0=> ALE<='0';START<='0';OE<='0';LOCK<='0'; next_state<=st1; WHEN st1=> ALE<='1';START<='0';OE<='0';LOCK<='0'; next_state<=st2; WHEN st2=> ALE<='0';START<='1';OE<='0';LOCK<='0'; next_state<=st3; WHEN st3=> ALE<='0';START<='0';OE<='0';LOCK<='0'; IF(EOC='1')THEN next_state<=st3; ELSE next_state<=st4; END IF; WHEN st4=> ALE<='0';START<='0';OE<='0';LOCK<='0'; IF (EOC='0') THEN next_state<=st4; ELSE next_state<=st5; END IF; WHEN st5=> ALE<='0';START<='0';OE<='1';LOCK<='0'; next_state<=st6; WHEN st6=> ALE<='0';START<='0';OE<='1';LOCK<='1'; next_state<=st0; WHEN OTHERS=> ALE<='0';START<='0';OE<='0';LOCK<='0'; next_state<=st0; END CASE; END PROCESS PRO; PROCESS(CLK) BEGIN IF(CLK'EVENT AND CLK='1')THEN current_state<=next_state; END IF; END PROCESS; PROCESS(LOCK) BEGIN IF LOCK='1' AND LOCK'EVENT THEN REGL<=D; END IF; END PROCESS; Q<=REGL; END ARCHITECTURE one; ARCHITECTURE behav OF AD IS BEGIN PROCESS(Q) BEGIN CASE Q IS WHEN "00000000" =>LED7S1 <="0111111";LED7S2 <="0111111";E<="00000"; WHEN "00000001" =>LED7S1 <="0111111";LED7S2 <="1011011";E<="00000"; WHEN "00000010" =>LED7S1 <="0111111";LED7S2 <="1100110";E<="00000"; WHEN "00000011" =>LED7S1 <="0111111";LED7S2 <="1111101";E<="00000"; WHEN "00000100" =>LED7S1 <="0111111";LED7S2 <="1111111";E<="00000"; WHEN "00000101" =>LED7S1 <="0000110";LED7S2 <="0111111";E<="00000"; WHEN "00000110" =>LED7S1 <="0000110";LED7S2 <="0000110";E<="00000"; WHEN "00000111" =>LED7S1 <="0000110";LED7S2 <="1100110";E<="00000"; WHEN "00001000" =>LED7S1 <="0000110";LED7S2 <="1111101";E<="00000"; WHEN "00001001" =>LED7S1 <="0000110";LED7S2 <="1111111";E<="00000"; WHEN "00001010" =>LED7S1 <="1011011";LED7S2 <="0111111";E<="00000"; WHEN "00001011" =>LED7S1 <="1011011";LED7S2 <="1011011";E<="00000"; WHEN "00001100" =>LED7S1 <="1011011";LED7S2 <="1100110";E<="00000"; WHEN "00001101" =>LED7S1 <="1011011";LED7S2 <="1101101";E<="00000"; WHEN "00001110" =>LED7S1 <="1011011";LED7S2 <="0000111";E<="00000"; WHEN "00001111" =>LED7S1 <="1011011";LED7S2 <="1101111";E<="00000"; WHEN "00010000" =>LED7S1 <="1001111";LED7S2 <="0000110";E<="00000"; WHEN "00010001" =>LED7S1 <="1001111";LED7S2 <="1001111";E<="00000"; WHEN "00010010" =>LED7S1 <="1001111";LED7S2 <="1101101";E<="00000"; WHEN "00010011" =>LED7S1 <="1001111";LED7S2 <="0000111";E<="00000"; WHEN "00010100" =>LED7S1 <="1001111";LED7S2 <="1101111";E<="00000"; WHEN "00010101" =>LED7S1 <="1100110";LED7S2 <="0000110";E<="00000"; WHEN "00010110" =>LED7S1 <="1100110";LED7S2 <="1001111";E<