keydecoder.vhd

FPGA EP1C6Q240C8 4*4键盘模块 4*4矩阵键盘

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;
ENTITY keydecoder_deb IS
PORT(
		keyin        :IN STD_LOGIC_VECTOR(3 DOWNTO 0);
		keydrv       :IN STD_LOGIC_VECTOR(3 DOWNTO 0);
		clk          :IN STD_LOGIC;
		clk_scan     :IN STD_LOGIC;
		keyvalue     :OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
		keypressed   :OUT STD_LOGIC;
		functionkey  :OUT STD_LOGIC		
		);
END keydecoder_deb;
ARCHITECTURE rtl OF keydecoder_deb IS
SIGNAL temp                     : STD_LOGIC_VECTOR(7 DOWNTO 0);
SIGNAL temp_pressed             : STD_LOGIC;
SIGNAL q1,q2,q3,q4,q5,q6        : STD_LOGIC;
SIGNAL keypressed_asy			: STD_LOGIC;
BEGIN
	temp<=keydrv & keyin;
	PROCESS(temp)
	BEGIN
		CASE temp IS
			WHEN "11101110"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';
			WHEN "11101101"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';
			WHEN "11101011"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';	
			WHEN "11100111"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';
			WHEN "11011110"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';
			WHEN "11011101"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';
			WHEN "11011011"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';	
			WHEN "11010111"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';
			WHEN "10111110"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='1';
			WHEN "10111101"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';
			WHEN "10111011"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='1';	
			WHEN "10110111"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='1';
			WHEN "01111110"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='0';
			WHEN "01111101"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='1';
			WHEN "01111011"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='1';	
			WHEN "01110111"=>keyvalue<=CONV_STD_LOGIC_VECTOR(1,4);
								temp_pressed<='1';
								functionkey <='1';
			WHEN OTHERS    =>   temp_pressed<='0';
		END CASE;
	END PROCESS;
	PROCESS(clk_scan)
	BEGIN
		IF(clk_scan'event and clk_scan='1') THEN
			q1<=temp_pressed;
			q2<=q1;
			q3<=q2;
			q4<=q3;
		END IF;
		keypressed_asy <= q1 OR q2 OR q3 OR q4;
	END PROCESS;
	PROCESS(clk)
	BEGIN
		IF(clk'event and clk='1') THEN
			q5<=temp_pressed;
			q6<=q5;
		END IF;
		keypressed<=q5 AND NOT(q6);
	END PROCESS;
END rtl;