eccgen256byte.vhd.bak

基于xilinx ISE环境开发的VHDL的NAND flash ECC 实现,eccGen256Byte 文件夹为ECC 产生程序

----------------------------------------------------------------------------------
-- Company: 
-- Engineer: Zhuo Zhihai
-- 
-- Create Date:    17:30:28 04/06/2008 
-- Design Name: 
-- Module Name:    eccGen256byte - Behavioral 
-- Project Name: 
-- Target Devices: 
-- Tool versions: 
-- Description: 
--
-- Dependencies: 
--
-- Revision: 
-- Revision 0.01 - File Created
-- Additional Comments: 
--
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library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

---- Uncomment the following library declaration if instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity eccGen256byte is
    Port ( reset : in  STD_LOGIC;	--active high
           clk : in  STD_LOGIC;
           data : in  STD_LOGIC_VECTOR (7 downto 0);
			  ND		: in STD_LOGIC;	-- new data input for ecc calculate
           eccValid : out  STD_LOGIC;
           eccCode : out  STD_LOGIC_VECTOR (23 downto 0));
end eccGen256byte;

architecture Behavioral of eccGen256byte is

component eccTab256
	port (
	a: IN std_logic_VECTOR(7 downto 0);
	clk: IN std_logic;
	qspo: OUT std_logic_VECTOR(7 downto 0));
END component;

signal P8H,P8L		: std_logic;	-- P8 P8'
signal P16H,P16L	: std_logic;	-- P16 P16'
signal P32H,P32L	: std_logic;	-- P32 P32'
signal P64H,P64L	: std_logic;	-- P64 P64'
signal P128H,P128L: std_logic;	-- P128 P128'
signal P256H,P256L: std_logic;	-- P256 P256'
signal P512H,P512L: std_logic;	-- P512 P512'
signal P1024H,P1024L	: std_logic;-- P1024 P1024'
signal eccTab_dout	: std_logic_vector(7 downto 0);

signal eccCode_3	: std_logic_vector(7 downto 0);	-- ecc code byte 3

signal dataCount	: std_logic_vector(7 downto 0);

signal eccValid_pre	: std_logic;
begin



eccCode(7 downto 0) <= eccCode_3;
eccCode(23 downto 16) <= P64H & P64L & p32H & P32L & p16H & P16L & p8H & P8L;
eccCode(15 downto 8)  <= P1024H & P1024L & P512H & P512L & p256H & P256L & p128H & P128L;

inst_eccTab: eccTab256
	port map(
	a	=>	data,
	clk=> clk,
	qspo=> eccTab_dout);
	
process(reset,clk)
begin
	if reset = '1' then
		dataCount <= (others => '0');
	elsif clk'event and clk = '1' then
		if ND = '1' then
			dataCount <= dataCount + '1';
		end if;
	end if;
end process;

--- generate eccCode
process(reset,clk)
begin
	if reset = '1' then
	
		P8H 	<= '0';P8L <= '0';
		P16H 	<= '0';P16L <= '0';
		P32H 	<= '0';P32L <= '0';
		P64H 	<= '0';P64L <= '0';
		P128H <= '0';P128L <= '0';
		P256H <= '0';P256L <= '0';
		P512H <= '0';P512L <= '0';
		P1024H <= '0';P1024L <= '0';
		eccCode_3 <= (1=> '1',0 =>'1',others =>'0');

		eccValid<= '0';

		eccValid_pre <= '0';
	elsif clk'event and clk ='1' then

		if dataCount = x"FF" then

			eccValid_pre <= '1';

		else 

			eccValid_pre <= '0';

		end if;

		eccValid	<= eccValid_pre;	

		if dataCount = x"00" and ND = '0' hen

			P8H 	<= '0';P8L <= '0';
			P16H 	<= '0';P16L <= '0';
			P32H 	<= '0';P32L <= '0';
			P64H 	<= '0';P64L <= '0';
			P128H <= '0';P128L <= '0';
			P256H <= '0';P256L <= '0';
			P512H <= '0';P512L <= '0';
			P1024H <= '0';P1024L <= '0';
			eccCode_3 <= (others =>'0');			

		end if;
		if ND = '1' then
		eccCode_3 <= eccCode_3 xor eccTab_dout;
		if dataCount(0) = '1' then
			P8H<= P8H xor eccTab_dout(7);	--P8
		else
			P8L<= P8L xor eccTab_dout(7); --P8'
		end if;
		
		if dataCount(1) ='1' then
			P16H <= P16H xor eccTab_dout(7);
		else
			P16L <= P16L xor eccTab_dout(7);
		end if;
    
		if dataCount(2) ='1'then
			P32H <= P32H xor eccTab_dout(7);
		else
			P32L <= P32L xor eccTab_dout(7);
		end if;	
		if dataCount(3) ='1'then
			P64H <= P64H xor eccTab_dout(7);
		else
			P64L <= P64L xor eccTab_dout(7);
		end if;											
		if dataCount(4) ='1'then
			P128H <= P128H xor eccTab_dout(7);
		else
			P128L <= P128L xor eccTab_dout(7);
		end if;		
		if dataCount(5) ='1'then
			P256H <= P256H xor eccTab_dout(7);
		else
			P256L <= P256L xor eccTab_dout(7);
		end if;	
		if dataCount(6) ='1'then
			P512H <= P512H xor eccTab_dout(7);
		else
			P512L <= P512L xor eccTab_dout(7);
		end if;	
		if dataCount(7) ='1'then
			P1024H <= P1024H xor eccTab_dout(7);
		else
			P1024L <= P1024L xor eccTab_dout(7);
		end if;
	end if;
end process;

end Behavioral;