Question

急求四人抢答器vhdl语言编的 ！！高手速来帮忙！！

急求啊 请大家帮帮忙！！

Answer 1

library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_arith.all; use ieee.std_logic_unsigned.all; -------------------------------------------------------------------- entity exp5 is port( S1,S2,S3,S4 : in std_logic; --输入：表示4个人 S5 : in std_logic; --主持人按键 D1,D2,D3,D4 : out std_logic --抢答结果显示 ); end exp5; -------------------------------------------------------------------- architecture behave of exp5 is signal Enable_Flag : std_logic; signal S : std_logic_vector(3 downto 0); begin process(S1,S2,S3,S4,S5) --允许抢答控制 begin S<=S1&S2&S3&S4; if(S5='0') then Enable_Flag<='1'; elsif(S/="1111") then Enable_Flag<='0'; end if; end process; process(S1,S2,S3,S4,S5) --抢答结果显示 begin if(S5='0') then D1<='0'; D2<='0'; D3<='0'; D4<='0'; elsif(Enable_Flag='1') then if(S1='0') then D1<='1'; elsif(S2='0') then D2<='1'; elsif(S3='0') then D3<='1'; elsif(S4='0') then D4<='1'; end if; end if; end process; end behave;