shaomiaode.vhd

VHDL电子抢答器的实现。有多个文件

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY shaomiaode IS
PORT(
		CP:IN STD_LOGIC; 
		SEGOUT	:OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
		SELOUT 	:OUT STD_LOGIC_VECTOR(5 DOWNTO 0);
		djs,d1,d2,d3,d4,fen :in std_logic_vector(3 downto 0)
	);--djs是到抢答的限制时间
END  shaomiaode;


ARCHITECTURE A OF  shaomiaode IS

SIGNAL Q :STD_LOGIC_VECTOR(2 DOWNTO 0);


BEGIN
		
PROCESS(CP)

	BEGIN
    		IF CP'EVENT AND CP = '1' THEN 
			Q <= Q+1;
		END IF;
    	END PROCESS;

--Q start from 1,so it's wrong to shaomiao from 0,
SELOUT   <= "000001"WHEN Q = 1 ELSE  --位选，后面补了两个0
			"000010"WHEN Q = 2 ELSE
			"000100"WHEN Q = 3 ELSE
			"001000"WHEN Q = 4 ELSE
			"010000"WHEN Q = 5 ELSE
            "100000"WHEN Q = 6 ELSE
			"000000";

SEGOUT   <= d1 WHEN Q = 1 ELSE
			d2 WHEN Q = 2 ELSE
			d3 WHEN Q = 3 ELSE
			d4 WHEN Q = 4 ELSE
		   djs WHEN Q = 5 ELSE
           fen WHEN Q = 6 ELSE
			"1111";

END A;