jens
55ee041c08
git-svn-id: http://moon:8086/svn/vhdl/trunk@1421 cc03376c-175c-47c8-b038-4cd826a8556b
64 lines
1.9 KiB
VHDL
64 lines
1.9 KiB
VHDL
-------------------------------------------------------------------------
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-- Project: JCPU, a portable 8-bit RISC CPU written in VHDL
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-- This file: Dual-ported register file with asynchrous read
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-- Copyright (C) 2007 J. Ahrensfeld
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-- This library is free software; you can redistribute it and/or
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-- modify it under the terms of the GNU Lesser General Public
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-- License as published by the Free Software Foundation; either
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-- version 2.1 of the License, or (at your option) any later version.
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-- This library is distributed in the hope that it will be useful,
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-- but WITHOUT ANY WARRANTY; without even the implied warranty of
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-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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-- Lesser General Public License for more details.
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-- You should have received a copy of the GNU Lesser General Public
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-- License along with this library; if not, write to the Free Software
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-- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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-- For questions and ideas, please contact the author at jens@jayfield.org
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-----------------------------------------------------------------------
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library IEEE;
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use IEEE.STD_LOGIC_1164.ALL;
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use IEEE.numeric_std.ALL;
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entity xmem_dual is
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Generic (
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addr_width : integer := 3;
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data_width : integer := 8
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);
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Port (
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clk : in STD_LOGIC;
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we : in STD_LOGIC;
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addr_w : in unsigned (addr_width-1 downto 0);
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addr_r : in unsigned (addr_width-1 downto 0);
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din : in unsigned (data_width-1 downto 0);
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dout : out unsigned (data_width-1 downto 0)
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);
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end xmem_dual;
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architecture Behavioral of xmem_dual is
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constant depth : integer := 2**addr_width;
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type RAMtype is array (0 to depth-1) of unsigned (data_width-1 downto 0);
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signal RAM : RAMtype;
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begin
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process (clk)
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begin
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if clk'event and clk = '1' then
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if we = '1' then
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RAM(to_integer(addr_w)) <= din;
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end if;
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dout <= RAM(to_integer(addr_r));
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end if;
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end process;
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end Behavioral;
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