core.vhd

一个很不错的cordic利用流水线计算正余弦的程序

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--  File: core.vhd                                       --
--  created : July 09,2001 15:00                         --
--  mail to [e-mail]                          --
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library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.STD_LOGIC_ARITH.all;
use IEEE.STD_LOGIC_SIGNED.all;

entity core is
	port (
		clk        : in  STD_LOGIC;
		x_in       : in  STD_LOGIC_VECTOR (15 downto 0);
		y_in       : in  STD_LOGIC_VECTOR (15 downto 0);
		octant_in  : in  STD_LOGIC_VECTOR (2 downto 0);
		octant_out : out STD_LOGIC_VECTOR (2 downto 0);
		radius     : out STD_LOGIC_VECTOR (19 downto 0);
		angle      : out STD_LOGIC_VECTOR (18 downto 0)
		);
end core;

architecture core of core is    
	
component stage is 	
	generic (iteration : integer);
		port (
			clk        : in  STD_LOGIC;
			x_in       : in  STD_LOGIC_VECTOR (19 downto 0);
			y_in       : in  STD_LOGIC_VECTOR (19 downto 0);
			z_in       : in  STD_LOGIC_VECTOR (18 downto 0);
			x_out      : out STD_LOGIC_VECTOR (19 downto 0);
			y_out      : out STD_LOGIC_VECTOR (19 downto 0);
			z_out      : out STD_LOGIC_VECTOR (18 downto 0);
			octant_in  : in  STD_LOGIC_VECTOR (2 downto 0);
			octant_out : out STD_LOGIC_VECTOR (2 downto 0)
			
			);
	end component stage;								   

	type XYvect is array(0 to 15) of std_logic_vector (19 downto 0); 
	type Zvect  is array(0 to 15) of std_logic_vector (18 downto 0); 
	type Ovect  is array(0 to 15) of std_logic_vector (2 downto 0); 

	signal rad    : std_logic_vector (19 downto 0); 
	signal angl   : std_logic_vector (18 downto 0); 
	signal octant : std_logic_vector (2 downto 0); 

	
	signal X : XYvect;
	signal Y : XYvect;
	signal Z : Zvect;
	signal O : Ovect;           
	
	
begin         
	
	X(0)(19 downto 4) <= x_in ;
	Y(0)(19 downto 4) <= y_in ;
	L1:    for i in 0 to 3 generate x(0)(i) <='0'; end generate;
	L2:    for i in 0 to 3 generate y(0)(i) <='0'; end generate;
	Z(0) <= (others => '0'); 
	O(0) <= octant_in;      
	
	gst:for i in 1 to 15 generate
		st : stage 
		generic map( 
			iteration => i
			)
		port map (
			clk        => clk,
			x_in       => X(i-1),
			y_in       => Y(i-1),
			z_in       => Z(i-1),
			x_out      => X(i),
			y_out      => y(i),
			z_out      => z(i),
			octant_in  => O(i-1),
			octant_out =>O(i)
			);
	end generate;

	radius     <= x(15);
	angle      <= z(15);
	octant_out <= o(15);    

end core;