Subversion Repositories uart2bus

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-- uart test bench   

--

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use std.textio.all;

library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_unsigned.all;

use ieee.numeric_std.all;

use ieee.std_logic_textio.all;

library work;

use work.uart2BusTop_pkg.all;

use work.helpers_pkg.all;

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-- test bench implementation 

entity uart2BusTop_txt_tb is

end uart2BusTop_txt_tb;

architecture behavior of uart2BusTop_txt_tb is

  procedure sendSerial(data : integer; baud : in real; parity : in integer; stopbit : in real; bitnumber : in integer; baudError : in real; signal txd : inout std_logic) is

    variable shiftreg : std_logic_vector(7 downto 0);

    variable bitTime  : time;

    begin

      bitTime := 1000 ms / (baud + baud * baudError / 100.0);

      shiftreg := std_logic_vector(to_unsigned(data, shiftreg'length));

      txd <= '0';

      wait for bitTime;

      for index in 0 to bitnumber loop

        txd <= shiftreg(index);

        wait for bitTime;

      end loop;

      txd <= '1';

      wait for stopbit * bitTime;

    end procedure;

  procedure recvSerial( signal rxd : in std_logic; baud : in real; parity : in integer; stopbit : in real; bitnumber : in integer; baudError : in real; signal data : inout std_logic_vector(7 downto 0)) is

    variable bitTime  : time;

    begin

      bitTime := 1000 ms / (baud + baud * baudError / 100.0);

      wait until (rxd = '0');

      wait for bitTime / 2;

      wait for bitTime;

      for index in 0 to bitnumber loop

        data <= rxd & data(7 downto 1);

        wait for bitTime;

      end loop;

      wait for stopbit * bitTime;

    end procedure;

  -- Inputs

  signal clr            : std_logic := '0';

  signal clk            : std_logic := '0';

  signal serIn          : std_logic := '0';

  signal intRdData      : std_logic_vector(7 downto 0) := (others => '0');

        -- Outputs

  signal serOut         : std_logic;

  signal intAddress     : std_logic_vector(7 downto 0);

  signal intWrData      : std_logic_vector(7 downto 0);

  signal intWrite       : std_logic;

  signal intRead        : std_logic;

  signal recvData       : std_logic_vector(7 downto 0);

  signal newRxData      : std_logic;

  signal intAccessReq   : std_logic;

  signal intAccessGnt   : std_logic;

  signal counter        : integer;

  constant BAUD_115200  : real := 115200.0;

  constant BAUD_38400   : real := 38400.0;

  constant BAUD_28800   : real := 28800.0;

  constant BAUD_19200   : real := 19200.0;

  constant BAUD_9600    : real := 9600.0;

  constant BAUD_4800    : real := 4800.0;

  constant BAUD_2400    : real := 2400.0;

  constant BAUD_1200    : real := 1200.0;

  constant NSTOPS_1     : real := 1.0;

  constant NSTOPS_1_5   : real := 1.5;

  constant NSTOPS_2     : real := 2.0;

  constant PARITY_NONE  : integer := 0;

  constant PARITY_EVEN  : integer := 1;

  constant PARITY_ODD   : integer := 2;

  constant PARITY_MARK  : integer := 3;

  constant PARITY_SPACE : integer := 4;

  constant NBITS_7      : integer := 6;

  constant NBITS_8      : integer := 7;

  begin

    -- Instantiate the Unit Under Test (UUT)

    uut : uart2BusTop

      port map

      (

        clr => clr,

        clk => clk,

        serIn => serIn,

        serOut => serOut,

        intAccessReq => intAccessReq,

        intAccessGnt => intAccessGnt,

        intRdData => intRdData,

        intAddress => intAddress,

        intWrData => intWrData,

        intWrite => intWrite,

        intRead => intRead

      );

    rfm : regFileModel

    port map

    (

      clr => clr,

      clk => clk,

      intRdData => intRdData,

      intAddress => intAddress,

      intWrData => intWrData,

      intWrite => intWrite,

      intRead => intRead);

    -- just to create a delay similar to simulate a bus arbitrer

    process (clr, clk)

    begin

      if (clr = '1') then

        intAccessGnt <= '0';

        counter <= 0;

      elsif (rising_edge(clk)) then

        if (counter = 0) then

          if ((intAccessReq = '1') and (intAccessGnt = '0')) then

            counter <= 500;

          end if;

          intAccessGnt <= '0';

        elsif (counter = 1) then

          counter <= counter - 1;

          intAccessGnt <= '1';

        else

          counter <= counter - 1;

        end if;

      end if;

    end process;

    -- clock generator - 25MHz clock 

    process

    begin

      clk <= '0';

      wait for 20 ns;

      clk <= '1';

      wait for 20 ns;

    end process;

    -- reset process definitions

    process

    begin

      clr <= '1';

      wait for 40 ns;

      clr <= '0';

      wait;

    end process;

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

    -- test bench receiver 

    process

    begin

      newRxData <= '0';

      recvData <= (others => '0');

      wait until (clr = '0');

      loop

        recvSerial(serOut, BAUD_115200, PARITY_NONE, NSTOPS_1, NBITS_8, 0.0, recvData);

        newRxData <= '1';

        wait for 25 ns;

        newRxData <= '0';

      end loop;

    end process;

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

    -- uart transmit - test bench control 

    process

      type     dataFile is file of character;

      file     testTextFile : dataFile open READ_MODE is "../test.txt";

      variable charBuf      : character;

      variable data         : integer;

      variable tempLine     : line;

    begin

          -- default value of serial output 

      serIn <= '1';

      -- text mode simulation 

      write(tempLine, string'("Starting text mode simulation"));

      writeline(output, tempLine);

      wait until (clr = '0');

      wait until (rising_edge(clk));

      for index in 0 to 99 loop

        wait until (rising_edge(clk));

      end loop;

      while not endfile(testTextFile) loop

        -- transmit the byte in the command file one by one 

        read(testTextFile, charBuf);

        data := character'pos(charBuf);

        sendSerial(data, BAUD_115200, PARITY_NONE, NSTOPS_1, NBITS_8, 0.0, serIn);

        wait for 800 us;

      end loop;

      wait;

    end process;

  end;