cr_file.vhdl

   1 library ieee;
   2 use ieee.std_logic_1164.all;
   3 use ieee.numeric_std.all;
   4
   5 library work;
   6 use work.common.all;
   7
   8 entity cr_file is
   9         port(
  10                 clk   : in std_logic;
  11
  12                 d_in  : in Decode2ToCrFileType;
  13                 d_out : out CrFileToDecode2Type;
  14
  15                 w_in  : in WritebackToCrFileType
  16         );
  17 end entity cr_file;
  18
  19 architecture behaviour of cr_file is
  20         signal crs : std_ulogic_vector(31 downto 0) := (others => '0');
  21 begin
  22         -- synchronous writes
  23         cr_write_0: process(clk)
  24                 variable hi, lo : integer := 0;
  25         begin
  26                 if rising_edge(clk) then
  27                         if w_in.write_cr_enable = '1' then
  28                                 report "Writing " & to_hstring(w_in.write_cr_data) & " to CR mask " & to_hstring(w_in.write_cr_mask);
  29
  30                                 for i in 0 to 7 loop
  31                                         if w_in.write_cr_mask(i) = '1' then
  32                                                 lo := i*4;
  33                                                 hi := lo + 3;
  34                                                 crs(hi downto lo) <= w_in.write_cr_data(hi downto lo);
  35                                         end if;
  36                                 end loop;
  37                         end if;
  38                 end if;
  39         end process cr_write_0;
  40
  41         -- asynchronous reads
  42         cr_read_0: process(all)
  43                 variable hi, lo : integer := 0;
  44         begin
  45                 --lo := (7-d_in.read_cr_nr_1)*4;
  46                 --hi := lo + 3;
  47
  48                 --report "read " & integer'image(d_in.read_cr_nr_1) & " from CR " & to_hstring(crs(hi downto lo));
  49                 --d_out.read_cr_data_1 <= crs(hi downto lo);
  50
  51                 -- Also return the entire CR to make mfcrf easier for now
  52                 report "read CR " & to_hstring(crs);
  53                 d_out.read_cr_data <= crs;
  54
  55 --              -- Forward any written data
  56 --              if w_in.write_cr_enable = '1' then
  57 --                      if d_in.read_cr_nr_1 = w_in.write_cr_nr then
  58 --                              d_out.read_cr_data_1 <= w_in.write_cr_data;
  59 --                      end if;
  60 --                      if d_in.read_cr_nr_2 = w_in.write_cr_nr then
  61 --                              d_out.read_cr_data_2 <= w_in.write_cr_data;
  62 --                      end if;
  63 --              end if;
  64         end process cr_read_0;
  65 end architecture behaviour;