Subversion Repositories leros

--
--  Copyright 2011 Martin Schoeberl <masca@imm.dtu.dk>,
--                 Technical University of Denmark, DTU Informatics. 
--  All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are met:
-- 
--    1. Redistributions of source code must retain the above copyright notice,
--       this list of conditions and the following disclaimer.
-- 
--    2. Redistributions in binary form must reproduce the above copyright
--       notice, this list of conditions and the following disclaimer in the
--       documentation and/or other materials provided with the distribution.
-- 
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
-- OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-- OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
-- NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
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-- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-- LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-- ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-- THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-- 
-- The views and conclusions contained in the software and documentation are
-- those of the authors and should not be interpreted as representing official
-- policies, either expressed or implied, of the copyright holder.
-- 
 
 
--
--	leros_de2-70.vhd
--
--	top level for Altera DE2-70 board
--
--	2011-02-20	creation
--
--
 
 
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
 
use work.leros_types.all;
 
 
entity leros_top_de2 is
 
port (
	clk : in std_logic;
	oLEDG : out std_logic_vector(7 downto 0);
	iKEY : in std_logic_vector(3 downto 0);	
	ser_txd			: out std_logic;
	ser_rxd			: in std_logic
);
end leros_top_de2;
 
architecture rtl of leros_top_de2 is
 
	signal clk_int			: std_logic;
 
	-- for generation of internal reset
	signal int_res			: std_logic;
	signal res_cnt			: unsigned(2 downto 0) := "000";	-- for the simulation
 
	attribute altera_attribute : string;
	attribute altera_attribute of res_cnt : signal is "POWER_UP_LEVEL=LOW";
 
	signal ioout : io_out_type;
	signal ioin : io_in_type;
 
	signal outp : std_logic_vector(15 downto 0);
	signal btn_reg : std_logic_vector(3 downto 0);
 
 
begin
 
	-- clk input is 50 MHz
	-- for now 100 MHz is enough
	pll_inst : entity work.pll generic map(
		multiply_by => 2,
		divide_by => 1
	)
	port map (
		inclk0	 => clk,
		c0	 => clk_int
	);
 
--
--	internal reset generation
--	should include the PLL lock signal
--
process(clk_int)
begin
	if rising_edge(clk_int) then
		if (res_cnt/="111") then
			res_cnt <= res_cnt+1;
		end if;
		int_res <= not res_cnt(0) or not res_cnt(1) or not res_cnt(2);
	end if;
end process;
 
 
	cpu: entity work.leros
		port map(clk_int, int_res, ioout, ioin);
 
--	ioin.rddata(15 downto 4) <= (others => '0');
 
	ua: entity work.uart generic map (
		clk_freq => 100000000,
		baud_rate => 115200,
		txf_depth => 1,
		rxf_depth => 1
	)
	port map(
		clk => clk_int,
		reset => int_res,
 
		address => ioout.addr(0),
		wr_data => ioout.wrdata,
		rd => ioout.rd,
		wr => ioout.wr,
		rd_data => ioin.rddata,
 
		txd	 => ser_txd,
		rxd	 => ser_rxd
	);
 
process(clk_int)
begin
 
	if rising_edge(clk_int) then
		if ioout.wr='1' then
			outp <= ioout.wrdata;
		end if;
		oLEDG <= outp(7 downto 0);
		btn_reg <= iKEY;
--		ioin.rddata(3 downto 0) <= not btn_reg;
	end if;
end process;
 
end rtl;