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MGTEVB

ScaleSpy

Documentation for architecture MGTEVB/ScaleSpy/a0

VHDL Contents

    1  -- EASE/HDL begin --------------------------------------------------------------
    2  -- 
    3  -- Architecture 'a0' of entity 'ScaleSpy'.
    4  -- 
    5  --------------------------------------------------------------------------------
    6  -- 
    7  -- Copy of the interface declaration:
    8  -- 
    9  --   port(
   10  --     Clk        : in     std_logic;
   11  --     Decr       : in     std_logic;
   12  --     EnH        : in     std_logic;
   13  --     EnL        : in     std_logic;
   14  --     LengthFull : in     std_logic;
   15  --     P          : in     std_logic_vector(31 downto 0);
   16  --     Rst_n      : in     std_logic;
   17  --     SpyActive  : out    std_logic;
   18  --     SpyWEN     : out    std_logic);
   19  -- 
   20  -- EASE/HDL end ----------------------------------------------------------------
   21  
   22  architecture a0 of ScaleSpy is
   23  
   24    signal SendSpyEvt : std_logic;
   25  
   26  begin
   27  
   28  --  SpyWEN <= '1' when (SendSpyEvt = '1' and EnH = '1' and EnL = '0') else '0';
   29  
   30    SpyActive<= SendSpyEvt;
   31  
   32    pr1:
   33    process (Clk, Rst_n)
   34      variable cnt: unsigned(15 downto 0);
   35    begin       
   36      if (Rst_n = '0') then
   37        cnt := (others => '0');
   38        SendSpyEvt <= '0';
   39        SpyWEN <= '0';
   40      elsif (rising_edge(Clk)) then
   41  
   42  -- Pipeline step needed since there is also a pipeline step in the MGTData path
   43        if (SendSpyEvt = '1' and EnH = '1' and EnL = '0' and LengthFull = '0') then
   44          SpyWEN <= '1';
   45        else
   46          SpyWEN <= '0';
   47        end if;
   48  
   49        if (Decr = '1') then
   50          if (cnt = 0) then
   51            cnt := unsigned(P(15 downto 0));  -- reload counter (only 16 bits)
   52            if (P(16) = '1') then
   53              SendSpyEvt <= '1';              -- if enabled: send event 
   54            else
   55              SendSpyEvt <= '0';
   56            end if;
   57          else
   58            cnt := cnt - 1;
   59            SendSpyEvt <= '0';
   60          end if;
   61        end if;
   62      end if;
   63    end process;
   64  
   65  end architecture a0 ; -- of ScaleSpy
   66  
   67