library ieee;
  use ieee.std_logic_1164.all;
  use ieee.numeric_std.all;

--+ including vhdl 2008 libraries
--+ These lines can be commented out when using
--+ a simulator with built-in VHDL 2008 support
--library ieee_proposed;
--  use ieee_proposed.standard_additions.all;
--  use ieee_proposed.std_logic_1164_additions.all;
--  use ieee_proposed.numeric_std_additions.all;

library osvvm;
  use osvvm.RandomPkg.all;

library libvhdl;
  use libvhdl.AssertP.all;
  use libvhdl.SimP.all;
  use libvhdl.QueueP.all;



entity SpiT is
end entity SpiT;



architecture sim of SpiT is


  component SpiMasterE is
    generic (
      G_DATA_WIDTH   : positive := 8;
      G_DATA_DIR     : natural range 0 to 1 := 0;
      G_SPI_CPOL     : natural range 0 to 1 := 0;
      G_SPI_CPHA     : natural range 0 to 1 := 0;
      G_SCLK_DIVIDER : positive range 6 to positive'high := 10
    );
    port (
      --+ system if
      Reset_n_i    : in  std_logic;
      Clk_i        : in  std_logic;
      --+ SPI slave if
      SpiSclk_o    : out std_logic;
      SpiSte_o     : out std_logic;
      SpiMosi_o    : out std_logic;
      SpiMiso_i    : in  std_logic;
      --+ local VAI if
      Data_i       : in  std_logic_vector(G_DATA_WIDTH-1 downto 0);
      DataValid_i  : in  std_logic;
      DataAccept_o : out std_logic;
      Data_o       : out std_logic_vector(G_DATA_WIDTH-1 downto 0);
      DataValid_o  : out std_logic;
      DataAccept_i : in  std_logic
    );
  end component SpiMasterE;


  component SpiSlaveE is
    generic (
      G_DATA_WIDTH : positive := 8;
      G_DATA_DIR   : natural range 0 to 1 := 0;
      G_SPI_CPOL   : natural range 0 to 1 := 0;
      G_SPI_CPHA   : natural range 0 to 1 := 0
    );
    port (
      --+ system if
      Reset_n_i    : in  std_logic;
      Clk_i        : in  std_logic;
      --+ SPI slave if
      SpiSclk_i    : in  std_logic;
      SpiSte_i     : in  std_logic;
      SpiMosi_i    : in  std_logic;
      SpiMiso_o    : out std_logic;
      --+ local VAI if
      Data_i       : in  std_logic_vector(G_DATA_WIDTH-1 downto 0);
      DataValid_i  : in  std_logic;
      DataAccept_o : out std_logic;
      Data_o       : out std_logic_vector(G_DATA_WIDTH-1 downto 0);
      DataValid_o  : out std_logic;
      DataAccept_i : in  std_logic
    );
  end component SpiSlaveE;


  --* testbench global clock period
  constant C_PERIOD     : time := 5 ns;
  --* SPI data transfer data width
  constant C_DATA_WIDTH : natural := 8;

  --* testbench global clock
  signal s_clk     : std_logic := '0';
  --* testbench global reset
  signal s_reset_n : std_logic := '0';

  --* SPI mode range subtype
  subtype t_spi_mode is natural range 0 to 3;

  --+ test done array with entry for each test
  signal s_test_done : boolean_vector(t_spi_mode'low to 4*t_spi_mode'high+3) := (others => false);


begin


  --* testbench global clock
  s_clk <= not(s_clk) after C_PERIOD/2 when not(and_reduce(s_test_done)) else '0';
  --* testbench global reset
  s_reset_n <= '1' after 100 ns;



  --* Generate tests for both direction
  DataDirectionG : for direction in 0 to 1 generate


    --* Generate SpiMasterE tests for all 4 modes
    SpiMastersG : for mode in t_spi_mode'low to t_spi_mode'high generate


      signal s_sclk : std_logic;
      signal s_ste  : std_logic;
      signal s_mosi : std_logic;
      signal s_miso : std_logic;

      signal s_din         : std_logic_vector(C_DATA_WIDTH-1 downto 0);
      signal s_din_valid   : std_logic;
      signal s_din_accept  : std_logic;
      signal s_dout        : std_logic_vector(C_DATA_WIDTH-1 downto 0);
      signal s_dout_valid  : std_logic;
      signal s_dout_accept : std_logic;

      shared variable sv_mosi_queue : t_list_queue;
      shared variable sv_miso_queue : t_list_queue;


    begin


        QueueInitP : process is
        begin
          sv_mosi_queue.init(32);
          sv_miso_queue.init(32);
          wait;
        end process QueueInitP;


      --* Stimuli generator and BFM for the valid-accept interface
      --* on the local data input of the DUT
      --*
      --* Generates random stimuli and serves it to the
      --* valid-accept interface at the input of the DUT
      --*
      --* The stimuli data is also pushed into the mosi queue
      --* which serves as simple abstract reference model
      --* of the SPI transmit (master -> slave) channel
      SpiMasterStimP : process is
        variable v_random : RandomPType;
      begin
        v_random.InitSeed(v_random'instance_name);
        s_din_valid <= '0';
        s_din       <= (others => '0');
        wait until s_reset_n = '1';
        for i in 0 to integer'(2**C_DATA_WIDTH-1) loop
          s_din <= v_random.RandSlv(C_DATA_WIDTH);
          s_din_valid <= '1';
          wait until rising_edge(s_clk) and s_din_accept = '1';
          s_din_valid <= '0';
          sv_mosi_queue.push(s_din);
          wait until rising_edge(s_clk);
        end loop;
        wait;
      end process SpiMasterStimP;


      --* DUT: SpiMasterE component
      i_SpiMasterE : SpiMasterE
      generic map (
        G_DATA_WIDTH   => C_DATA_WIDTH,
        G_DATA_DIR     => direction,
        G_SPI_CPOL     => mode / 2,
        G_SPI_CPHA     => mode mod 2,
        G_SCLK_DIVIDER => 10
      )
      port map (
        --+ system if
        Reset_n_i    => s_reset_n,
        Clk_i        => s_clk,
        --+ SPI slave if
        SpiSclk_o    => s_sclk,
        SpiSte_o     => s_ste,
        SpiMosi_o    => s_mosi,
        SpiMiso_i    => s_miso,
        --+ local VAI if
        Data_i       => s_din,
        DataValid_i  => s_din_valid,
        DataAccept_o => s_din_accept,
        Data_o       => s_dout,
        DataValid_o  => s_dout_valid,
        DataAccept_i => s_dout_accept
      );


      --* Checker and BFM for the valid-accept interface
      --* on the local data output of the DUT
      --*
      --* Reads the output of the DUT and compares it to
      --* data popped from the miso queue which serves as
      --* simple abstract reference model of the SPI receive
      --* (slave -> master) channel
      SpiMasterCheckP : process is
        variable v_queue_data : std_logic_vector(C_DATA_WIDTH-1 downto 0) := (others => '0');
      begin
        s_dout_accept <= '0';
        wait until s_reset_n = '1';
        for i in 0 to integer'(2**C_DATA_WIDTH-1) loop
          wait until rising_edge(s_clk) and s_dout_valid = '1';
          s_dout_accept <= '1';
          sv_miso_queue.pop(v_queue_data);
          assert_equal(s_dout, v_queue_data);
          wait until rising_edge(s_clk);
          s_dout_accept <= '0';
        end loop;
        report "INFO: SpiMaster (direction=" & to_string(direction) & ", mode=" & to_string(mode) & ") test successfully";
        s_test_done(mode+direction*4) <= true;
        wait;
      end process SpiMasterCheckP;


      --* Stimuli generator and BFM  for the SPI slave
      --* interface on the SPI miso input of the DUT
      --*
      --* Generates random stimuli and serves it to the
      --* SPI interface at the input of the DUT
      --*
      --* The stimuli data is also pushed into the miso queue
      --* which serves as simple abstract reference model
      --* of the SPI receive (slave -> master) channel
      --*
      --* Furthermore the data received by the SPI slave BFM
      --* is checked against data popped from the mosi queue
      --* which serves as simple abstract reference model of
      --* the SPI receive (master -> slave) channel
      SpiSlaveP : process is
        variable v_send_data    : std_logic_vector(C_DATA_WIDTH-1 downto 0) := (others => '0');
        variable v_receive_data : std_logic_vector(C_DATA_WIDTH-1 downto 0) := (others => '0');
        variable v_queue_data   : std_logic_vector(C_DATA_WIDTH-1 downto 0) := (others => '0');
        variable v_random       : RandomPType;
      begin
        v_random.InitSeed(v_random'instance_name);
        s_miso <= 'Z';
        wait until s_reset_n = '1';
        for i in 0 to integer'(2**C_DATA_WIDTH-1) loop
          v_send_data := v_random.RandSlv(C_DATA_WIDTH);
          sv_miso_queue.push(v_send_data);
          spi_slave (data_in  => v_send_data,
                     data_out => v_receive_data,
                     sclk     => s_sclk,
                     ste      => s_ste,
                     mosi     => s_mosi,
                     miso     => s_miso,
                     dir      => direction,
                     cpol     => mode / 2,
                     cpha     => mode mod 2
          );
          sv_mosi_queue.pop(v_queue_data);
          assert_equal(v_receive_data, v_queue_data);
        end loop;
        wait;
      end process SpiSlaveP;


    end generate SpiMastersG;


    --* Generate SpiMasterE tests for all 4 modes
    SpiSlavesG : for mode in t_spi_mode'low to t_spi_mode'high generate


      signal s_sclk : std_logic;
      signal s_ste  : std_logic;
      signal s_mosi : std_logic;
      signal s_miso : std_logic;

      signal s_din         : std_logic_vector(C_DATA_WIDTH-1 downto 0);
      signal s_din_valid   : std_logic;
      signal s_din_accept  : std_logic;
      signal s_dout        : std_logic_vector(C_DATA_WIDTH-1 downto 0);
      signal s_dout_valid  : std_logic;
      signal s_dout_accept : std_logic;

      shared variable sv_mosi_queue : t_list_queue;
      shared variable sv_miso_queue : t_list_queue;


    begin


        QueueInitP : process is
        begin
          sv_mosi_queue.init(32);
          sv_miso_queue.init(32);
          wait;
        end process QueueInitP;


      --* Unit test of spi master procedure, checks all combinations
      --* of cpol & cpha against spi slave procedure
      SpiMasterP : process is
        variable v_send_data    : std_logic_vector(C_DATA_WIDTH-1 downto 0) := (others => '0');
        variable v_receive_data : std_logic_vector(C_DATA_WIDTH-1 downto 0) := (others => '0');
        variable v_queue_data   : std_logic_vector(C_DATA_WIDTH-1 downto 0) := (others => '0');
        variable v_random       : RandomPType;
      begin
        v_random.InitSeed(v_random'instance_name);
        s_sclk     <= '1';
        s_ste      <= '1';
        s_mosi     <= '1';
        wait until s_reset_n = '1';
        for i in 0 to integer'(2**C_DATA_WIDTH-1) loop
          v_send_data := v_random.RandSlv(C_DATA_WIDTH);
          sv_mosi_queue.push(v_send_data);
          spi_master (data_in  => v_send_data,
                      data_out => v_receive_data,
                      sclk     => s_sclk,
                      ste      => s_ste,
                      mosi     => s_mosi,
                      miso     => s_miso,
                      dir      => direction,
                      cpol     => mode / 2,
                      cpha     => mode mod 2,
                      period   => C_PERIOD * 10
          );
          sv_miso_queue.pop(v_queue_data);
          assert_equal(v_receive_data, v_queue_data);
        end loop;
        report "INFO: SpiSlave (direction=" & to_string(direction) & ", mode=" & to_string(mode) & ") test successfully";
        s_test_done(mode+8+direction*4) <= true;
        wait;
      end process SpiMasterP;


      SpiSlaveStimP : process is
        variable v_random : RandomPType;
      begin
        v_random.InitSeed(v_random'instance_name);
        s_din_valid <= '0';
        s_din       <= (others => '0');
        wait until s_reset_n = '1';
        for i in 0 to integer'(2**C_DATA_WIDTH-1) loop
          s_din <= v_random.RandSlv(C_DATA_WIDTH);
          s_din_valid <= '1';
          wait until rising_edge(s_clk) and s_din_accept = '1';
          s_din_valid <= '0';
          sv_miso_queue.push(s_din);
          wait until rising_edge(s_clk) and s_dout_valid = '1';
        end loop;
        wait;
      end process SpiSlaveStimP;


      i_SpiSlaveE : SpiSlaveE
      generic map (
        G_DATA_WIDTH => C_DATA_WIDTH,
        G_DATA_DIR   => direction,
        G_SPI_CPOL   => mode / 2,
        G_SPI_CPHA   => mode mod 2
      )
      port map (
        --+ system if
        Reset_n_i    => s_reset_n,
        Clk_i        => s_clk,
        --+ SPI slave if
        SpiSclk_i    => s_sclk,
        SpiSte_i     => s_ste,
        SpiMosi_i    => s_mosi,
        SpiMiso_o    => s_miso,
        --+ local VAI if
        Data_i       => s_din,
        DataValid_i  => s_din_valid,
        DataAccept_o => s_din_accept,
        Data_o       => s_dout,
        DataValid_o  => s_dout_valid,
        DataAccept_i => s_dout_accept
      );


      SpiSlaveCheckP : process is
        variable v_queue_data : std_logic_vector(C_DATA_WIDTH-1 downto 0) := (others => '0');
      begin
        s_dout_accept <= '0';
        wait until s_reset_n = '1';
        for i in 0 to integer'(2**C_DATA_WIDTH-1) loop
          wait until rising_edge(s_clk) and s_dout_valid = '1';
          s_dout_accept <= '1';
          sv_mosi_queue.pop(v_queue_data);
          assert_equal(s_dout, v_queue_data);
          wait until rising_edge(s_clk);
          s_dout_accept <= '0';
        end loop;
        wait;
      end process SpiSlaveCheckP;


    end generate SpiSlavesG;


  end generate DataDirectionG;


end architecture sim;