1 -- `Deep Thought', a softcore CPU implemented on a FPGA
3 -- Copyright (C) 2010 Markus Hofstaetter <markus.manrow@gmx.at>
4 -- Copyright (C) 2010 Martin Perner <e0725782@student.tuwien.ac.at>
5 -- Copyright (C) 2010 Stefan Rebernig <stefan.rebernig@gmail.com>
6 -- Copyright (C) 2010 Manfred Schwarz <e0725898@student.tuwien.ac.at>
7 -- Copyright (C) 2010 Bernhard Urban <lewurm@gmail.com>
9 -- This program is free software: you can redistribute it and/or modify
10 -- it under the terms of the GNU General Public License as published by
11 -- the Free Software Foundation, either version 3 of the License, or
12 -- (at your option) any later version.
14 -- This program is distributed in the hope that it will be useful,
15 -- but WITHOUT ANY WARRANTY; without even the implied warranty of
16 -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 -- GNU General Public License for more details.
19 -- You should have received a copy of the GNU General Public License
20 -- along with this program. If not, see <http://www.gnu.org/licenses/>.
24 use IEEE.std_logic_1164.all;
25 use IEEE.numeric_std.all;
27 use work.common_pkg.all;
30 architecture behaviour of ram_xilinx is
31 type word_t is array (0 to 3) of std_logic_vector(7 downto 0);
32 subtype stfu_t is std_logic_vector(BYTE_WIDTH-1 downto 0);
33 type ram_t is array (0 to (2**ADDR_WIDTH)-1) of stfu_t;
34 signal ram0 : ram_t := (others => x"00");
35 signal ram1 : ram_t := (others => x"00");
36 signal ram2 : ram_t := (others => x"00");
37 signal ram3 : ram_t := (others => x"00");
38 signal q_local : word_t;
40 begin -- Re-organize the read data from the RAM to match the output
41 unpack: for i in 0 to 3 generate
42 q(8*(i+1) - 1 downto 8*i) <= q_local(i);
47 if(rising_edge(clk)) then
50 ram0(to_integer(UNSIGNED(waddr))) <= wdata(7 downto 0);
53 ram1(to_integer(UNSIGNED(waddr))) <= wdata(15 downto 8);
56 ram2(to_integer(UNSIGNED(waddr))) <= wdata(23 downto 16);
59 ram3(to_integer(UNSIGNED(waddr))) <= wdata(31 downto 24);
62 q_local(0) <= ram0(to_integer(UNSIGNED(raddr)));
63 q_local(1) <= ram1(to_integer(UNSIGNED(raddr)));
64 q_local(2) <= ram2(to_integer(UNSIGNED(raddr)));
65 q_local(3) <= ram3(to_integer(UNSIGNED(raddr)));
69 end architecture behaviour;