Subversion Repositories sdram_controller

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-- Company: OPL Aerospatiale AG

-- Engineer: Owen Lynn <lynn0p@hotmail.com>

-- 

-- Create Date:    23:22:19 07/27/2009 

-- Design Name: 

-- Module Name:    scratch - impl 

-- Project Name: 

-- Target Devices: 

-- Tool versions: 

-- Description: Testbench for the DDR SDRAM controller. Sends a write command, sends a read 

--  and outputs to the led on the Spartan3e Starter Board

--

-- Dependencies: 

--

-- Revision: 

-- Revision 0.01 - File Created

-- Additional Comments: 

--  Copyright (c) 2009 Owen Lynn <lynn0p@hotmail.com>

--  Released under the GNU Lesser General Public License, Version 3

--

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library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

library UNISIM;

use UNISIM.VComponents.all;

entity scratch is

        port(         clk : in  std_logic;

                     clke : in  std_logic;

                      rst : in  std_logic;

                 led : out std_logic_vector( 7 downto 0 );

                        -- SDRAM pins out

                          dram_clkp   : out   std_logic;

                          dram_clkn   : out   std_logic;

                          dram_clke   : out   std_logic;

                          dram_cs     : out   std_logic;

                          dram_cmd    : out   std_logic_vector(2 downto 0);

                          dram_bank   : out   std_logic_vector(1 downto 0);

                          dram_addr   : out   std_logic_vector(12 downto 0);

                          dram_dm     : out   std_logic_vector(1 downto 0);

                          dram_dqs    : inout std_logic_vector(1 downto 0);

                          dram_dq     : inout std_logic_vector(15 downto 0);

                        -- debug signals

                          debug_reg   : out std_logic_vector(7 downto 0)

                          );

end scratch;

architecture impl of scratch is

        type DRAM_DRIVER_STATES is ( STATE0, STATE1, STATE2, STATE3, STATE4, STATE5 );

        signal dram_driver_state : DRAM_DRIVER_STATES := STATE0;

        signal clk_bufd  : std_logic;

        signal op      : std_logic_vector(1 downto 0);

        signal addr    : std_logic_vector(25 downto 0);

        signal op_ack  : std_logic;

        signal busy_n  : std_logic;

        signal data_i  : std_logic_vector(7 downto 0);

        signal debug   : std_logic_vector(7 downto 0);

begin

        BUFG_CLK: BUFG

        port map(

                O => clk_bufd,

                I => clk

        );

        SDRAM: entity work.sdram_controller

        port map(

                clk50mhz => clk_bufd,

                en => '1',

           reset => rst,

           op => op,

           addr => addr,

           op_ack => op_ack,

           busy_n => busy_n,

           data_o => led,

           data_i => data_i,

                dram_clkp => dram_clkp,

                dram_clkn => dram_clkn,

                dram_clke => dram_clke,

                dram_cs => dram_cs,

                dram_cmd => dram_cmd,

                dram_bank => dram_bank,

                dram_addr => dram_addr,

                dram_dm => dram_dm,

                dram_dqs => dram_dqs,

                dram_dq => dram_dq,

                debug_reg => debug

        );

        debug_reg <= debug;

        process(clk_bufd, clke)

        begin

                if (clke = '0') then

                        dram_driver_state <= STATE0;

                elsif (rising_edge(clk_bufd)) then

                        case dram_driver_state is

                                when STATE0 =>

                                        if (busy_n = '1') then

                                                dram_driver_state <= STATE1;

                                        end if;

                                when STATE1 =>

                                        addr <= "01000000000000000000000111";

                                        data_i <= "11111111";

                                        op <= "10";

                                        if (op_ack = '1') then

                                                dram_driver_state <= STATE2;

                                        end if;

                                when STATE2 =>

                                        op <= "00";

                                        if (busy_n = '1') then

                                                dram_driver_state <= STATE3;

                                        end if;

                                when STATE3 =>

                                        addr <= "01000000000000000000000111";

                                        op <= "01";

                                        if (op_ack = '1') then

                                                dram_driver_state <= STATE4;

                                        end if;

                                when STATE4 =>

                                        op <= "00";

                                        if (busy_n = '1') then

                                                dram_driver_state <= STATE5;

                                        end if;

                                when STATE5 =>

                                        dram_driver_state <= STATE5;

                        end case;

                end if;

        end process;

end impl;