Subversion Repositories rs232_interface

----------------------------------------------------------------------------------

-- Creation Date: 13:07:48 27/03/2011 

-- Module Name: RS232/UART Interface - Testbench

-- Used TAB of 4 Spaces

----------------------------------------------------------------------------------

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity uart_tb is

end uart_tb;

architecture Behavioral of uart_tb is

        ----------------------------------------------

        -- Constants

        ----------------------------------------------

        constant MAIN_CLK_PER   :       time := 20 ns;          -- 50 MHz

        constant MAIN_CLK     : integer := 50;

        constant BAUD_RATE              :       integer := 9600;        -- Bits per Second

        constant RST_LVL                :       std_logic := '1';       -- Active Level of Reset

        ----------------------------------------------

        -- Signal Declaration

        ----------------------------------------------

        -- Clock and reset Signals

        signal clk_50m                                  :       std_logic := '0';

        signal rst                                              :       std_logic;

        -- Transceiver Interface

        signal data_from_transceiver    :       std_logic;

        signal data_to_transceiver              :       std_logic;

        -- Configuration signals

        signal par_en                                   :       std_logic;

        -- uPC Interface

        signal tx_req                                   :       std_logic;

        signal tx_end                                   :       std_logic;

        signal tx_data                                  :       std_logic_vector(7 downto 0) := x"5A";

        signal rx_ready                                 :       std_logic;

        signal rx_data                                  :       std_logic_vector(7 downto 0);

        -- Testbench Signals

        signal uart_clk                                 :       std_logic := '0';

begin

        ----------------------------------------------

        -- Components Instantiation

        ----------------------------------------------

        uut:entity work.uart

        generic map(

                CLK_FREQ        => MAIN_CLK,                            -- Main frequency (MHz)

                SER_FREQ        => BAUD_RATE                            -- Baud rate (bps)

        )

        port map(

                -- Control

                clk                     => clk_50m,                                     -- Main clock

                rst                     => rst,                                         -- Main reset

                -- External Interface

                rx                      => data_from_transceiver,       -- RS232 received serial data

                tx                      => data_to_transceiver,         -- RS232 transmitted serial data

                -- RS232/UART Configuration

                par_en          => par_en,                                      -- Parity bit enable

                -- uPC Interface

                tx_req          => '1',                                 -- Request SEND of data

                tx_end          => tx_end,                                      -- Data SENDED

                tx_data         => tx_data,                                     -- Data to transmit

                rx_ready        => rx_ready,                            -- Received data ready to uPC read

                rx_data         => rx_data                                      -- Received data 

        );

        ----------------------------------------------

        -- Main Signals Generation

        ----------------------------------------------

        -- Main Clock generation

        main_clock_generation:process

        begin

                wait for MAIN_CLK_PER/2;

                clk_50m         <= not clk_50m;

        end process;

        -- UART Clock generation

        uart_clock_generation:process

        begin

                wait for (MAIN_CLK_PER*5208)/2;

                uart_clk        <= not uart_clk;

        end process;

        -- Reset generation

        rst     <=      RST_LVL, not RST_LVL after MAIN_CLK_PER*5;

   data_from_transceiver <= data_to_transceiver;

end Behavioral;