Subversion Repositories neorv32

-- # ********************************************************************************************* #

-- # ********************************************************************************************* #

-- # Main data and address ALU. Includes comparator unit and co-processor interface/arbiter.       #

-- # Main data and address ALU. Includes comparator unit and co-processor interface/arbiter.       #

-- # ********************************************************************************************* #

-- # ********************************************************************************************* #

-- # BSD 3-Clause License                                                                          #

-- # BSD 3-Clause License                                                                          #

-- #                                                                                               #

-- #                                                                                               #

-- #                                                                                               #

-- #                                                                                               #

-- # Redistribution and use in source and binary forms, with or without modification, are          #

-- # Redistribution and use in source and binary forms, with or without modification, are          #

-- # permitted provided that the following conditions are met:                                     #

-- # permitted provided that the following conditions are met:                                     #

-- #                                                                                               #

-- #                                                                                               #

-- # 1. Redistributions of source code must retain the above copyright notice, this list of        #

-- # 1. Redistributions of source code must retain the above copyright notice, this list of        #

    imm_i       : in  std_ulogic_vector(data_width_c-1 downto 0); -- immediate

    imm_i       : in  std_ulogic_vector(data_width_c-1 downto 0); -- immediate

    -- data output --

    -- data output --

    cmp_o       : out std_ulogic_vector(1 downto 0); -- comparator status

    cmp_o       : out std_ulogic_vector(1 downto 0); -- comparator status

    res_o       : out std_ulogic_vector(data_width_c-1 downto 0); -- ALU result

    res_o       : out std_ulogic_vector(data_width_c-1 downto 0); -- ALU result

    add_o       : out std_ulogic_vector(data_width_c-1 downto 0); -- address computation result

    add_o       : out std_ulogic_vector(data_width_c-1 downto 0); -- address computation result

    -- co-processor interface --

    -- co-processor interface --

    cp0_start_o : out std_ulogic; -- trigger co-processor 0

    cp0_start_o : out std_ulogic; -- trigger co-processor 0

    cp0_data_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- co-processor 0 result

    cp0_data_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- co-processor 0 result

    cp0_valid_i : in  std_ulogic; -- co-processor 0 result valid

    cp0_valid_i : in  std_ulogic; -- co-processor 0 result valid

    cp1_start_o : out std_ulogic; -- trigger co-processor 1

    cp1_start_o : out std_ulogic; -- trigger co-processor 1

  -- Operand Mux ----------------------------------------------------------------------------

  -- Operand Mux ----------------------------------------------------------------------------

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

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

  opa <= pc2_i when (ctrl_i(ctrl_alu_opa_mux_c) = '1') else rs1_i; -- operand a (first ALU input operand), only required for arithmetic ops

  opa <= pc2_i when (ctrl_i(ctrl_alu_opa_mux_c) = '1') else rs1_i; -- operand a (first ALU input operand), only required for arithmetic ops

  opb <= imm_i when (ctrl_i(ctrl_alu_opb_mux_c) = '1') else rs2_i; -- operand b (second ALU input operand)

  opb <= imm_i when (ctrl_i(ctrl_alu_opb_mux_c) = '1') else rs2_i; -- operand b (second ALU input operand)

  -- Comparator Unit ------------------------------------------------------------------------

  -- Comparator Unit ------------------------------------------------------------------------

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

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

  cmp_opx  <= (rs1_i(rs1_i'left) and (not ctrl_i(ctrl_alu_unsigned_c))) & rs1_i;

  cmp_opx  <= (rs1_i(rs1_i'left) and (not ctrl_i(ctrl_alu_unsigned_c))) & rs1_i;