crhelpers.vhdl

   1 library ieee;
   2 use ieee.std_logic_1164.all;
   3
   4 library work;
   5 use work.common.all;
   6
   7 package crhelpers is
   8         function fxm_to_num(fxm: std_ulogic_vector(7 downto 0)) return integer;
   9         function num_to_fxm(num: integer) return std_ulogic_vector;
  10         --function from_crfile(cr: crfile) return std_ulogic_vector;
  11         --function extract_one_crfield(cr: crfile; fxm: std_ulogic_vector(7 downto 0)) return std_ulogic_vector;
  12         --function insert_multiple_crfields(cr_in: crfile; rs: std_ulogic_vector(63 downto 0); fxm: std_ulogic_vector(7 downto 0)) return crfile;
  13         --function insert_one_crfield(cr_in: crfile; rs: std_ulogic_vector(63 downto 0); fxm: std_ulogic_vector(7 downto 0)) return crfile;
  14 end package crhelpers;
  15
  16 package body crhelpers is
  17
  18         function fxm_to_num(fxm: std_ulogic_vector(7 downto 0)) return integer is
  19         begin
  20                 -- If multiple fields are set (undefined), match existing
  21                 -- hardware by returning the first one.
  22                 for i in 0 to 7 loop
  23                         -- Big endian bit numbering
  24                         if fxm(7-i) = '1' then
  25                                 return i;
  26                         end if;
  27                 end loop;
  28
  29                 -- If no fields are set (undefined), also match existing
  30                 -- hardware by returning cr7.
  31                 return 7;
  32         end;
  33
  34         function num_to_fxm(num: integer) return std_ulogic_vector is
  35         begin
  36                 case num is
  37                         when 0 =>
  38                                 return "10000000";
  39                         when 1 =>
  40                                 return "01000000";
  41                         when 2 =>
  42                                 return "00100000";
  43                         when 3 =>
  44                                 return "00010000";
  45                         when 4 =>
  46                                 return "00001000";
  47                         when 5 =>
  48                                 return "00000100";
  49                         when 6 =>
  50                                 return "00000010";
  51                         when 7 =>
  52                                 return "00000001";
  53                         when others =>
  54                                 return "00000000";
  55                 end case;
  56         end;
  57
  58 --      function from_crfile(cr: crfile) return std_ulogic_vector is
  59 --              variable combined_cr : std_ulogic_vector(31 downto 0) := (others => '0');
  60 --              variable high, low: integer range 0 to 31 := 0;
  61 --      begin
  62 --              for i in 0 to cr'length-1 loop
  63 --                      low := 4*(7-i);
  64 --                      high := low+3;
  65 --                      combined_cr(high downto low) := cr(i);
  66 --              end loop;
  67 --
  68 --              return combined_cr;
  69 --      end function;
  70 --
  71 --      function extract_one_crfield(cr: crfile; fxm: std_ulogic_vector(7 downto 0)) return std_ulogic_vector is
  72 --              variable combined_cr : std_ulogic_vector(63 downto 0) := (others => '0');
  73 --              variable crnum: integer range 0 to 7 := 0;
  74 --      begin
  75 --              crnum := fxm_to_num(fxm);
  76 --
  77 --              -- Vivado doesn't support non constant vector slice
  78 --              -- low := 4*(7-crnum);
  79 --              -- high := low+3;
  80 --              -- combined_cr(high downto low) := cr(crnum);
  81 --              case_0: case crnum is
  82 --              when 0 =>
  83 --                  combined_cr(31 downto 28) := cr(0);
  84 --              when 1 =>
  85 --                  combined_cr(27 downto 24) := cr(1);
  86 --              when 2 =>
  87 --                  combined_cr(23 downto 20) := cr(2);
  88 --              when 3 =>
  89 --                  combined_cr(19 downto 16) := cr(3);
  90 --              when 4 =>
  91 --                  combined_cr(15 downto 12) := cr(4);
  92 --              when 5 =>
  93 --                  combined_cr(11 downto 8) := cr(5);
  94 --              when 6 =>
  95 --                  combined_cr(7 downto 4) := cr(6);
  96 --              when 7 =>
  97 --                  combined_cr(3 downto 0) := cr(7);
  98 --              end case;
  99 --
 100 --              return combined_cr;
 101 --      end;
 102 --
 103 --      function insert_multiple_crfields(cr_in: crfile; rs: std_ulogic_vector(63 downto 0); fxm: std_ulogic_vector(7 downto 0)) return crfile is
 104 --              variable cr : crfile;
 105 --              variable combined_cr : std_ulogic_vector(63 downto 0) := (others => '0');
 106 --              variable high, low: integer range 0 to 31 := 0;
 107 --      begin
 108 --              cr := cr_in;
 109 --
 110 --              for i in 0 to 7 loop
 111 --                      -- BE bit numbering
 112 --                      if fxm(7-i) = '1' then
 113 --                              low := 4*(7-i);
 114 --                              high := low+3;
 115 --                              cr(i) := rs(high downto low);
 116 --                      end if;
 117 --              end loop;
 118 --
 119 --              return cr;
 120 --      end;
 121 --
 122 --      function insert_one_crfield(cr_in: crfile; rs: std_ulogic_vector(63 downto 0); fxm: std_ulogic_vector(7 downto 0)) return crfile is
 123 --              variable cr : crfile;
 124 --              variable crnum: integer range 0 to 7 := 0;
 125 --              variable high, low: integer range 0 to 31 := 0;
 126 --      begin
 127 --              cr := cr_in;
 128 --              crnum := fxm_to_num(fxm);
 129 --              low := 4*(7-crnum);
 130 --              high := low+3;
 131 --              cr(crnum) := rs(high downto low);
 132 --              return cr;
 133 --      end;
 134 end package body crhelpers;