Subversion Repositories lxp32

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

-- Common package for LXP32 testbenches

--

-- Part of the LXP32 verification environment

--

-- Copyright (c) 2016 by Alex I. Kuznetsov

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

use std.textio.all;

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

package body common_pkg is

        impure function rand return integer is

                variable r: unsigned(63 downto 0);

        begin

                r:=rand_state*to_unsigned(1103515245,32)+12345;

                rand_state:=r(rand_state'range);

                return to_integer(rand_state(30 downto 16));

        end function;

        impure function rand(a: integer; b: integer) return integer is

        begin

                assert a<=b report "Invalid range" severity failure;

                return (rand mod (b-a+1))+a;

        end function;

        function hex_string(x: std_logic_vector) return string is

                variable xx: std_logic_vector(x'length-1 downto 0);

                variable i: integer:=0;

                variable ii: integer;

                variable c: integer;

                variable s: string(x'length downto 1);

        begin

                xx:=x;

                loop

                        ii:=i*4;

                        exit when ii>xx'high;

                        if ii+3<=xx'high then

                                c:=to_integer(unsigned(xx(ii+3 downto ii)));

                        else

                                c:=to_integer(unsigned(xx(xx'high downto ii)));

                        end if;

                        case c is

                        when 0 => s(i+1):='0';

                        when 1 => s(i+1):='1';

                        when 2 => s(i+1):='2';

                        when 3 => s(i+1):='3';

                        when 4 => s(i+1):='4';

                        when 5 => s(i+1):='5';

                        when 6 => s(i+1):='6';

                        when 7 => s(i+1):='7';

                        when 8 => s(i+1):='8';

                        when 9 => s(i+1):='9';

                        when 10 => s(i+1):='A';

                        when 11 => s(i+1):='B';

                        when 12 => s(i+1):='C';

                        when 13 => s(i+1):='D';

                        when 14 => s(i+1):='E';

                        when 15 => s(i+1):='F';

                        when others => s(i+1):='X';

                        end case;

                        i:=i+1;

                end loop;

                return s(i downto 1);

        end function;

end package body;