CristalCaveGem » LustreC » Lustrec-Tests

library ieee;

use ieee.std_logic_1164.all;

library ieee;

use ieee.numeric_std.all;

entity idctbuff is

	port (

		wa0_data : in  std_logic_vector(31 downto 0);

		wa0_addr : in  std_logic_vector(8 downto 0);

		clk : in  std_logic;

		ra2_data : out std_logic_vector(31 downto 0);

		ra2_addr : in  std_logic_vector(8 downto 0);

		ra1_data : out std_logic_vector(31 downto 0);

		ra1_addr : in  std_logic_vector(8 downto 0);

		ra0_addr : in  std_logic_vector(8 downto 0);

		ra0_data : out std_logic_vector(31 downto 0);

		wa0_en : in  std_logic

	);

end idctbuff;

architecture augh of idctbuff is

	-- Embedded RAM

	type ram_type is array (0 to 383) of std_logic_vector(31 downto 0);

	signal ram : ram_type := (others => (others => '0'));

	-- Little utility functions to make VHDL syntactically correct

	--   with the syntax to_integer(unsigned(vector)) when 'vector' is a std_logic.

	--   This happens when accessing arrays with <= 2 cells, for example.

	function to_integer(B: std_logic) return integer is

		variable V: std_logic_vector(0 to 0);

	begin

		V(0) := B;

		return to_integer(unsigned(V));

	end;

	function to_integer(V: std_logic_vector) return integer is

	begin

		return to_integer(unsigned(V));

	end;

begin

	-- Sequential process

	-- It handles the Writes

	process (clk)

	begin

		if rising_edge(clk) then

			-- Write to the RAM

			-- Note: there should be only one port.

			if wa0_en = '1' then

				ram( to_integer(wa0_addr) ) <= wa0_data;

			end if;

		end if;

	end process;

	-- The Read side (the outputs)

	ra1_data <= ram( to_integer(ra1_addr) ) when to_integer(ra1_addr) < 384 else (others => '-');

	ra0_data <= ram( to_integer(ra0_addr) ) when to_integer(ra0_addr) < 384 else (others => '-');

	ra2_data <= ram( to_integer(ra2_addr) ) when to_integer(ra2_addr) < 384 else (others => '-');

end architecture;