library ieee;use ieee.std_logic_1164.all;package pkg_util isfunction equal ( arg1, arg2 : std_logic_vector) return std_logic;function or_logic ( arg1, arg2 : std_logic) return std_logic;function and_logic ( arg1, arg2 : std_logic) return std_logic;function not_logic ( arg : std_logic) return std_logic;function conv_std_logic ( arg : boolean ) return std_logic;end pkg_util;package body pkg_util is-------------------------------------------------------------------------- Function for "==" translationfunction equal ( arg1, arg2 : std_logic_vector) return std_logicisbegin  if Is_X ( arg1 ) or Is_X ( arg2 )  then    return 'X';  elsif ( arg1 = arg2 )  then    return '1';  else    return '0';  end if;end equal;-------------------------------------------------------------------------- Function for "||" translationfunction or_logic ( arg1, arg2 : std_logic) return std_logicisbegin  if Is_X ( arg1) or Is_X ( arg2)  then    return 'X';  elsif (  arg1 = '1' or arg2 = '1' )  then    return '1';  else    return '0';  end if;end or_logic;-------------------------------------------------------------------------- Function for "&&" translationfunction and_logic ( arg1, arg2 : std_logic) return std_logicisbegin  if Is_X ( arg1) or Is_X ( arg2)  then    return 'X';  elsif (  arg1 = '1' and arg2 = '1' )  then    return '1';  else    return '0';  end if;end and_logic;-------------------------------------------------------------------------- Function for "not" translationfunction not_logic ( arg : std_logic) return std_logicisbegin  case (arg) is    when 'X' | 'Z' => return 'X';    when '1' => return '0';    when others => return '1';   end case;end not_logic;-------------------------------------------------------------------------- Function for conversion to std_logicfunction conv_std_logic ( arg : boolean ) return std_logic isbegin  if arg  then    return '1';  else    return '0';  end if;end;------------------------------------------------------------------------end pkg_util;