library ieee; use ieee.std_logic_1164.all; library ieee; use ieee.numeric_std.all; entity w_split4 is port ( clk : in std_logic; ra0_data : out std_logic_vector(7 downto 0); wa0_data : in std_logic_vector(7 downto 0); wa0_addr : in std_logic; wa0_en : in std_logic; ra0_addr : in std_logic ); end w_split4; architecture augh of w_split4 is -- Embedded RAM type ram_type is array (0 to 1) of std_logic_vector(7 downto 0); signal ram : ram_type := ( "00000111", "00000111" ); -- 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) ra0_data <= ram( to_integer(ra0_addr) ); end architecture;