keyscan66.txt

6*8VHDL按键扫描

--          KEY BOARD 
------------------------------------- 
--000  *A*   	*B*   	*C*		*D*		*E*		*F* 
 
--001  *G*   	*H*   	*I*		*J*		*K*		*L* 
 
--010  *M*   	*N*   	*O*		*P*		*Q*		*R* 
 
--011  *S*   	*T*   	*U*		*V*		*W*		*X* 
 
--100  *Y*   	*Z*   	*1*		*2*		*3*		*4* 
 
--101  *5*   	*6*   	*7*		*8*		*9*		*#* 
 
--	  000	001		010		011		100		101	 
-- 
-- 
 
 
 
library IEEE; 
use IEEE.std_logic_1164.all; 
use ieee.std_logic_unsigned.all; 
entity scan is 
    port ( 
        b: in STD_LOGIC_VECTOR (5 downto 0);	-- 列 
        row: buffer STD_LOGIC_VECTOR (5 downto 0);	--行 
        Cout: out STD_LOGIC_VECTOR (5 downto 0); 	-- 
        Irq: out STD_LOGIC; 
	    
	   clk: in STD_LOGIC; --时钟 
	   r: in STD_LOGIC			-- 复位 
    ); 
end scan; 
 
architecture scan_arch of scan is 
 
signal dd:STD_LOGIC_VECTOR (2 downto 0);	--行扫描计数器 
signal dd1:STD_LOGIC_VECTOR (2 downto 0);	--行译码信号 
signal line:STD_LOGIC_VECTOR (2 downto 0); 	--列译码信号 
signal keydown:std_logic;					 --按下键 
 
signal CCout: STD_LOGIC_VECTOR (5 downto 0);  
signal IIrq: STD_LOGIC; 
 
begin 
 
count: process (r, clk  ) 
	begin 
	if ( r='1' ) then dd<="000"; 
	elsif( clk'event and clk = '1') then 
			dd <= dd + '1'; 
			end if ; 
end process count ; 
 with dd select 
   row<=  "011111"	when"000", 
     	"101111"	when"001", 
     	"110111"	when"010", 
     	"111011"	when"011", 
		"111101"	when"100", 
		"111110"	when"101", 
     	"ZZZZZZ"	when others ; 
 
with row select 
   	  dd1<= 	"000"when"011111", 
     		"001"when"101111", 
     		"010"when"110111", 
     		"011"when"111011", 
			"100"when"111101", 
			"101"when"111110", 
     		"ZZZ"when others ; 
    
keydown<= b(0) and b(1) and b(2) and b(3) and b(4) and b(5); 
 
with b select 
  	line<= 	"000"when"011111", 
     		"001"when"101111", 
     		"010"when"110111", 
     		"011"when"111011", 
			"100"when"111101", 
			"101"when"111110", 
     		"ZZZ"when others ; 
    
 
process ( keydown,clk,r  ) 
begin 
	if ( r='1' ) then CCout<="000000"; 
					IIrq <= '0'; 
		elsif( clk'event and clk = '1') then 
   				if (keydown = '0') then 
      				CCout <= dd1&line ; 
	 				IIrq <= '1' ; 
    				end if; 
	end if; 
end process ; 
 
Cout <= CCout ; 
Irq <= IIrq; 
 
end scan_arch;