Subversion Repositories mod_sim_exp

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----  tdpramblock_asym                                            ---- 

----                                                              ---- 

----  This file is part of the                                    ----

----    Modular Simultaneous Exponentiation Core project          ---- 

----    http://www.opencores.org/cores/mod_sim_exp/               ---- 

----                                                              ---- 

----  Description                                                 ---- 

----    structural description of an asymmetric true dual port    ----

----    ram with one 32-bit read/write port and one (width)-bit   ----

----    read/write port.                                          ----

----                                                              ---- 

----  Dependencies: tdpram_asym                                   ----

----                                                              ----

----  Authors:                                                    ----

----      - Geoffrey Ottoy, DraMCo research group                 ----

----      - Jonas De Craene, JonasDC@opencores.org                ---- 

----                                                              ---- 

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----                                                              ---- 

---- Copyright (C) 2011 DraMCo research group and OPENCORES.ORG   ---- 

----                                                              ---- 

---- This source file may be used and distributed without         ---- 

---- restriction provided that this copyright statement is not    ---- 

---- removed from the file and that any derivative work contains  ---- 

---- the original copyright notice and the associated disclaimer. ---- 

----                                                              ---- 

---- This source file is free software; you can redistribute it   ---- 

---- and/or modify it under the terms of the GNU Lesser General   ---- 

---- Public License as published by the Free Software Foundation; ---- 

---- either version 2.1 of the License, or (at your option) any   ---- 

---- later version.                                               ---- 

----                                                              ---- 

---- This source is distributed in the hope that it will be       ---- 

---- useful, but WITHOUT ANY WARRANTY; without even the implied   ---- 

---- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ---- 

---- PURPOSE.  See the GNU Lesser General Public License for more ---- 

---- details.                                                     ---- 

----                                                              ---- 

---- You should have received a copy of the GNU Lesser General    ---- 

---- Public License along with this source; if not, download it   ---- 

---- from http://www.opencores.org/lgpl.shtml                     ---- 

----                                                              ---- 

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library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_unsigned.all;

use ieee.std_logic_arith.all;

library mod_sim_exp;

use mod_sim_exp.std_functions.all;

use mod_sim_exp.mod_sim_exp_pkg.all;

-- altera infers ramblocks from a depth of 9 (or 2 with any ram size recognition option on)

--    and width 64,128,256,512

-- xilinx infers ramblocks from a depth of 2 and width 32,64,128,256,512

entity tdpramblock_asym is

  generic (

    depth  : integer := 4;    -- nr of (width)-bit words

    width  : integer := 512;  -- width of portB

    device : string  := "xilinx"

  );

  port  (

    clk : in std_logic;

    -- port A 32-bit

    addrA : in std_logic_vector(log2((width*depth)/32)-1 downto 0);

    weA   : in std_logic;

    dinA  : in std_logic_vector(31 downto 0);

    doutA : out std_logic_vector(31 downto 0);

    -- port B (width)-bit

    addrB : in std_logic_vector(log2(depth)-1 downto 0);

    weB   : in std_logic;

    dinB  : in std_logic_vector(width-1 downto 0);

    doutB : out std_logic_vector(width-1 downto 0)

  );

end tdpramblock_asym;

architecture structural of tdpramblock_asym is

   -- constants

   constant nrRAMs    : integer := width/32;

   constant RAMwidthA : integer := 32/nrRAMs;

   -- interconnection signals

   type word_array is array (nrRAMs-1 downto 0) of std_logic_vector(31 downto 0);

   signal doutB_RAM : word_array;

   signal dinB_RAM  : word_array;

 begin

  ramblocks : for i in 0 to nrRAMs-1 generate

    ramblock : tdpram_asym

    generic map(

      widthA => RAMwidthA,

      depthB => depth,

      device => device

    )

    port map(

      clk => clk,

      -- port A (widthA)-bit

      addrA => addrA,

      weA   => weA,

      dinA  => dinA((i+1)*RAMwidthA-1 downto RAMwidthA*i),

      doutA => doutA((i+1)*RAMwidthA-1 downto RAMwidthA*i),

      -- port B 32-bit

      addrB => addrB,

      weB   => weB,

      dinB  => dinB_RAM(i),

      doutB => doutB_RAM(i)

    );

    map_ioB : for j in 0 to nrRAMs-1 generate

      -- output

      doutB(j*32+(i+1)*RAMwidthA-1 downto j*32+i*RAMwidthA)

          <= doutB_RAM(i)((j+1)*RAMwidthA-1 downto j*RAMwidthA);

      -- input

      dinB_RAM(i)((j+1)*RAMwidthA-1 downto j*RAMwidthA)

          <= dinB(j*32+(i+1)*RAMwidthA-1 downto j*32+i*RAMwidthA);

    end generate;

  end generate;

end structural;