Subversion Repositories 1g_ethernet_dpi

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--

--      Input file         : sram.vhd

--      Design name        : sram

--      Author             : Tamar Kranenburg

--      Company            : Delft University of Technology

--                         : Faculty EEMCS, Department ME&CE

--                         : Systems and Circuits group

--

--      Description        : Single Port Synchronous Random Access Memory

--

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library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_unsigned.all;

use ieee.std_logic_textio.all; -- InitRamFromFile

library std;

use std.textio.all; -- InitRamFromFile

library mblite;

use mblite.std_Pkg.all;

entity sram is generic

(

    FNAME : string;

    WIDTH : positive := 32;

    SIZE  : positive := 16

);

port

(

    dat_o : out std_logic_vector(WIDTH - 1 downto 0);

    dat_i : in std_logic_vector(WIDTH - 1 downto 0);

    adr_i : in std_logic_vector(SIZE - 1 downto 0);

    wre_i : in std_logic;

    ena_i : in std_logic;

    clk_i : in std_logic

);

end sram;

architecture arch of sram is

    type ram_type is array(2 ** SIZE - 1 downto 0) of std_logic_vector(WIDTH - 1 downto 0);

    --

    impure function InitRamFromFile (RamFileName : in string) return ram_type is

        FILE ramfile : text is in RamFileName;

        variable RamFileLine : line;

        variable ram : ram_type;

        variable i : natural := 0;

    begin

            while not endfile(ramfile) loop

                readline(ramfile, RamFileLine);

                hread(RamFileLine, ram(i));

                i := i + 1;

            end loop;

            return ram;

    end function;

    --

    signal ram :  ram_type := InitRamFromFile(FNAME);

begin

    process(clk_i)

    begin

        if rising_edge(clk_i) then

            if ena_i = '1' then

                if wre_i = '1' then

                   ram(my_conv_integer(adr_i)) <= dat_i;

                end if;

                dat_o <= ram(my_conv_integer(adr_i));

            end if;

        end if;

    end process;

end arch;