Subversion Repositories mips_fault_tolerant

library IEEE;

use IEEE.std_logic_1164.all;

use IEEE.numeric_std.all;

--use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity Reg_file_block is

port(

                Clk : in std_logic;

                rst : in  STD_LOGIC;

                vector_on : in std_logic_vector(2 downto 0);

                Reg_Write : in std_logic;

                Reg_Imm_not : in std_logic;

                rs : in std_logic_vector(4 downto 0);

                rt : in std_logic_vector(4 downto 0);

                rd : in std_logic_vector(4 downto 0);

                Bus_W : in std_logic_vector(31 downto 0);

                Bus_A : out std_logic_vector(31 downto 0);

                Bus_B : out std_logic_vector(31 downto 0)

);

end entity Reg_file_block;

architecture Reg_file of Reg_file_block is  --Regfile_block

-- Declarations of Register File type & signal

type Regfile_type is array (natural range<>) of std_logic_vector(31 downto 0);

signal Regfile_Coff : Regfile_type(0 to 31):= ((others=> (others=>'0')));

signal Addr_in : std_logic_vector(4 downto 0);

signal Bus_A_reg,Bus_B_reg : std_logic_vector(31 downto 0);

begin

process(Clk,rst,Reg_Write,Reg_Imm_not,rs,rt,rd,Bus_W,Regfile_Coff,vector_on)

variable adr : std_logic_vector(4 downto 0):= "00000";

Constant A_vector : std_logic_vector(31 Downto 0) := "00001110000000000000000000011011";

Constant B_vector : std_logic_vector(31 Downto 0) := "00001100000000000000000000011011";

begin

-- Regfile_Read Assignments

if(FALLING_EDGE(Clk))then

        Bus_A_reg <= Regfile_Coff(conv_integer(rs));

        Bus_B_reg <= Regfile_Coff(conv_integer(rt));

end if;

-- Write Address Assignment

if (Reg_Imm_Not = '1') then

                Addr_in <= rd;

        elsif (Reg_Imm_Not = '0') then

                Addr_in <= rt;

end if;

-- Vector initialize

if (((vector_on or "110") = "111") and (rst = '0')) then

   if vector_on  = "001" then

     adr := "10010";

          Regfile_Coff(conv_integer(Adr)) <= A_vector;

   elsif vector_on  = "011" then

          adr := "10011";

          Regfile_Coff(conv_integer(Adr)) <= B_vector;

        elsif vector_on  = "101" then

          adr := "01010";

          Regfile_Coff(conv_integer(Adr)) <= A_vector;

   elsif vector_on  = "111" then

          adr := "10001";

          Regfile_Coff(conv_integer(Adr)) <= B_vector;

        end if;

end if;

-- Regfile_Write Assignments

if rst = '0' then

   Addr_in <= "00000";

elsif(RISING_EDGE(Clk))then

        if(Reg_Write = '1' and Addr_in /= "00000") then

                Regfile_Coff(conv_integer(Addr_in)) <= Bus_W;

        end if;

end if;

if rst = '0' then

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

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

elsif(RISING_EDGE(Clk))then

Bus_A<=Bus_A_reg;

Bus_B<=Bus_B_reg;

end if;

end process;

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

end architecture Reg_file;