Subversion Repositories p9813_rgb_led_string_driver

-- A package containing various synthesizable functions useful in VHDL

--

-- Author : John Clayton

--

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use ieee.math_real.all;

use std.textio.all;

library work;

use work.function_pack.all;

package sim_support_pack is

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

-- function calls

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

    function string_to_integer (in_string : string) return integer ;

    function vector_to_string (in_vector : std_logic_vector) return string ;

    function char_to_bit (in_char : character) return std_logic ;

    function char_to_hex (in_char : character) return std_logic_vector ;

    function slv2string(in_vector : std_logic_vector; nibbles : natural) return string ;

    function u2string(in_vector : unsigned; nibbles : natural) return string ;

    function u2asciichar(in_vector : unsigned(7 downto 0)) return character ;

    function asciichar2u(in_char : character) return unsigned;

    function hex_to_ascii(in_vector : std_logic_vector; nibbles : natural) return string ;

    function u2ascii(in_vector : unsigned; nibbles : natural) return string ;

    function hex_data_wrd(in_vector : std_logic_vector) return string ;

    function hex_data_dblwrd(in_vector : std_logic_vector) return string ;

    function hex_data_dblwrdz(in_vector : std_logic_vector) return string ;

    function str2u2(s: string) return unsigned; -- Converts a string of ASCII characters into unsigned

    function is_hex(c : character) return boolean;

    function is_std_logic(c : character) return boolean;

    function is_space(c : character) return boolean;

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

-- procedures

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

end sim_support_pack;

package body sim_support_pack is

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

-- 

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

--* Title           :  TEST_PARITY

--* Filename & Ext  :  test_parity.vhdl

--* Author          :  David Bishop X-66788

--* Created         :  3/18/97

--* Version         :  1.2

--* Revision Date   :  97/04/15

--* SCCSid          :  1.2 04/15/97 test_parity.vhdl

--* WORK Library    :  testchip

--* Mod History     :  

--* Description     :  This is a parity generator which is written recursively

--*                 :  It is designed to test the ability of Simulation and

--*                 :  Synthesis tools to check this capability.

--* Known Bugs      :  

--* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

  function u_recursive_parity ( x : unsigned ) return std_logic is

    variable Upper, Lower : std_logic;

    variable Half : integer;

    variable BUS_int : unsigned( x'length-1 downto 0 );

    variable Result : std_logic;

  begin

    BUS_int := x;

    if ( BUS_int'length = 1 ) then

      Result := BUS_int ( BUS_int'left );

    elsif ( BUS_int'length = 2 ) then

      Result := BUS_int ( BUS_int'right ) xor BUS_int ( BUS_int'left );

    else

      Half := ( BUS_int'length + 1 ) / 2 + BUS_int'right;

      Upper := u_recursive_parity ( BUS_int ( BUS_int'left downto Half ));

      Lower := u_recursive_parity ( BUS_int ( Half - 1 downto BUS_int'right ));

      Result := Upper xor Lower;

    end if;

    return Result;

  end;

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

-- 

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

    function vector_to_string (in_vector : std_logic_vector) return string is

    variable out_string : string(32 downto 1);

    begin

      for i in in_vector'range loop

        if in_vector(i) = '1' then

          out_string(i+1) := '1';

        elsif in_vector(i) = '0' then

          out_string(i+1) := '0';

            else

                assert false

                report " illegal bit vector to bit string"

                severity note;

        end if;

      end loop;

      return out_string;

    end vector_to_string;

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

-- 

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

    function string_to_integer (in_string : string) return integer is

    variable int : integer := 0;

    begin

        for j in in_string'range loop

          case in_string(j) is

            when '0' => int := int;

            when '1' => int := int + (1 * 10**(j-1));

            when '2' => int := int + (2 * 10**(j-1));

            when '3' => int := int + (3 * 10**(j-1));

            when '4' => int := int + (4 * 10**(j-1));

            when '5' => int := int + (5 * 10**(j-1));

            when '6' => int := int + (6 * 10**(j-1));

            when '7' => int := int + (7 * 10**(j-1));

            when '8' => int := int + (8 * 10**(j-1));

            when '9' => int := int + (9 * 10**(j-1));

            when others =>

                assert false

                report " illegal character to integer"

                severity note;

          end case;

        end loop;

        return  int;

    end string_to_integer;

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

-- 

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

    function char_to_bit (in_char : character) return std_logic is

    variable out_bit : std_logic;

    begin

        if (in_char = '1') then

            out_bit := '1';

        elsif (in_char = '0') then

            out_bit := '0';

        else

            assert false

            report "illegal character to bit"

            severity note;

        end if;

        return out_bit;

    end char_to_bit;

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

-- 

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

    function char_to_hex (in_char : character) return std_logic_vector is

    variable out_vec : std_logic_vector(3 downto 0);

    begin

            case in_char is

              when '0' => out_vec := "0000";

              when '1' => out_vec := "0001";

              when '2' => out_vec := "0010";

              when '3' => out_vec := "0011";

              when '4' => out_vec := "0100";

              when '5' => out_vec := "0101";

              when '6' => out_vec := "0110";

              when '7' => out_vec := "0111";

              when '8' => out_vec := "1000";

              when '9' => out_vec := "1001";

              when 'A' | 'a' => out_vec := "1010";

              when 'B' | 'b' => out_vec := "1011";

              when 'C' | 'c' => out_vec := "1100";

              when 'D' | 'd' => out_vec := "1101";

              when 'E' | 'e' => out_vec := "1110";

              when 'F' | 'f' => out_vec := "1111";

              when others =>

                assert false

                report " illegal character to hex"

                severity note;

          end case;

        return out_vec;

    end char_to_hex;

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

-- 

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

    function slv2string(in_vector : std_logic_vector; nibbles : natural) return string is

    variable out_string : string(1 to nibbles);

    variable temp_in_vector : std_logic_vector(4*nibbles-1 downto 0);

    variable vector     : std_logic_vector(3 downto 0);

    begin

    temp_in_vector := in_vector(in_vector'length-1 downto in_vector'length-temp_in_vector'length);

        for i in 1 to nibbles loop

            vector := temp_in_vector((4*(nibbles-i)+3) downto 4*(nibbles-i));

            case vector is

                when "0000" => out_string(i) := '0';

                when "0001" => out_string(i) := '1';

                when "0010" => out_string(i) := '2';

                when "0011" => out_string(i) := '3';

                when "0100" => out_string(i) := '4';

                when "0101" => out_string(i) := '5';

                when "0110" => out_string(i) := '6';

                when "0111" => out_string(i) := '7';

                when "1000" => out_string(i) := '8';

                when "1001" => out_string(i) := '9';

                when "1010" => out_string(i) := 'A';

                when "1011" => out_string(i) := 'B';

                when "1100" => out_string(i) := 'C';

                when "1101" => out_string(i) := 'D';

                when "1110" => out_string(i) := 'E';

                when "1111" => out_string(i) := 'F';

                when others =>

                   out_string(i) := 'J';

                   assert false

                   report " illegal std_logic_vector to string"

                   severity note;

            end case;

        end loop;

        return out_string;

     end;

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

-- 

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

    function u2string(in_vector : unsigned; nibbles : natural) return string is

    variable out_string     : string(1 to nibbles);

    variable temp_in_vector : unsigned(4*nibbles-1 downto 0);

    variable vector         : unsigned(3 downto 0);

    begin

    temp_in_vector := in_vector(in_vector'length-1 downto in_vector'length-temp_in_vector'length);

        for i in 1 to nibbles loop

            vector := temp_in_vector((4*(nibbles-i)+3) downto 4*(nibbles-i));

            case vector is

                when "0000" => out_string(i) := '0';

                when "0001" => out_string(i) := '1';

                when "0010" => out_string(i) := '2';

                when "0011" => out_string(i) := '3';

                when "0100" => out_string(i) := '4';

                when "0101" => out_string(i) := '5';

                when "0110" => out_string(i) := '6';

                when "0111" => out_string(i) := '7';

                when "1000" => out_string(i) := '8';

                when "1001" => out_string(i) := '9';

                when "1010" => out_string(i) := 'A';

                when "1011" => out_string(i) := 'B';

                when "1100" => out_string(i) := 'C';

                when "1101" => out_string(i) := 'D';

                when "1110" => out_string(i) := 'E';

                when "1111" => out_string(i) := 'F';

                when others =>

                   out_string(i) := 'U';

                   assert false report " illegal unsigned to string" severity note;

            end case;

        end loop;

        return out_string;

     end;

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

-- 

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

    function u2asciichar(in_vector : unsigned(7 downto 0)) return character is

    variable out_char       : character;

    begin

      case in_vector is

          when "00001001" => out_char :=  HT; -- Horizontal Tab

          when "00100000" => out_char := ' ';

          when "00100001" => out_char := '!';

          when "00100010" => out_char := '"';

          when "00100011" => out_char := '#';

          when "00100100" => out_char := '$';

          when "00100101" => out_char := '%';

          when "00100110" => out_char := '&';

          when "00100111" => out_char := ''';

          when "00101000" => out_char := '(';

          when "00101001" => out_char := ')';

          when "00101010" => out_char := '*';

          when "00101011" => out_char := '+';

          when "00101100" => out_char := ',';

          when "00101101" => out_char := '-';

          when "00101110" => out_char := '.';

          when "00101111" => out_char := '/';

          when "00110000" => out_char := '0';

          when "00110001" => out_char := '1';

          when "00110010" => out_char := '2';

          when "00110011" => out_char := '3';

          when "00110100" => out_char := '4';

          when "00110101" => out_char := '5';

          when "00110110" => out_char := '6';

          when "00110111" => out_char := '7';

          when "00111000" => out_char := '8';

          when "00111001" => out_char := '9';

          when "00111010" => out_char := ':';

          when "00111011" => out_char := ';';

          when "00111100" => out_char := '<';

          when "00111101" => out_char := '=';

          when "00111110" => out_char := '>';

          when "00111111" => out_char := '?';

          when "01000000" => out_char := '@';

          when "01000001" => out_char := 'A';

          when "01000010" => out_char := 'B';

          when "01000011" => out_char := 'C';

          when "01000100" => out_char := 'D';

          when "01000101" => out_char := 'E';

          when "01000110" => out_char := 'F';

          when "01000111" => out_char := 'G';

          when "01001000" => out_char := 'H';

          when "01001001" => out_char := 'I';

          when "01001010" => out_char := 'J';

          when "01001011" => out_char := 'K';

          when "01001100" => out_char := 'L';

          when "01001101" => out_char := 'M';

          when "01001110" => out_char := 'N';

          when "01001111" => out_char := 'O';

          when "01010000" => out_char := 'P';

          when "01010001" => out_char := 'Q';

          when "01010010" => out_char := 'R';

          when "01010011" => out_char := 'S';

          when "01010100" => out_char := 'T';

          when "01010101" => out_char := 'U';

          when "01010110" => out_char := 'V';

          when "01010111" => out_char := 'W';

          when "01011000" => out_char := 'X';

          when "01011001" => out_char := 'Y';

          when "01011010" => out_char := 'Z';

          when "01011011" => out_char := '[';

          when "01011100" => out_char := '\';

          when "01011101" => out_char := ']';

          when "01011110" => out_char := '^';

          when "01011111" => out_char := '_';

          when "01100000" => out_char := '`';

          when "01100001" => out_char := 'a';

          when "01100010" => out_char := 'b';

          when "01100011" => out_char := 'c';

          when "01100100" => out_char := 'd';

          when "01100101" => out_char := 'e';

          when "01100110" => out_char := 'f';

          when "01100111" => out_char := 'g';

          when "01101000" => out_char := 'h';

          when "01101001" => out_char := 'i';

          when "01101010" => out_char := 'j';

          when "01101011" => out_char := 'k';

          when "01101100" => out_char := 'l';

          when "01101101" => out_char := 'm';

          when "01101110" => out_char := 'n';

          when "01101111" => out_char := 'o';

          when "01110000" => out_char := 'p';

          when "01110001" => out_char := 'q';

          when "01110010" => out_char := 'r';

          when "01110011" => out_char := 's';

          when "01110100" => out_char := 't';

          when "01110101" => out_char := 'u';

          when "01110110" => out_char := 'v';

          when "01110111" => out_char := 'w';

          when "01111000" => out_char := 'x';

          when "01111001" => out_char := 'y';

          when "01111010" => out_char := 'z';

          when "01111011" => out_char := '{';

          when "01111100" => out_char := '|';

          when "01111101" => out_char := '}';

          when "01111110" => out_char := '~';

          when others =>

             out_char := '*';

             --assert false report " illegal unsigned to ascii character" severity note;

      end case;

      return out_char;

     end;

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

--

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

    function asciichar2u(in_char : character) return unsigned is

    variable out_vect : unsigned(7 downto 0);

    begin

      case in_char is

          when  HT => out_vect := "00001001";

          when ' ' => out_vect := "00100000";

          when '!' => out_vect := "00100001";

          when '"' => out_vect := "00100010";

          when '#' => out_vect := "00100011";

          when '$' => out_vect := "00100100";

          when '%' => out_vect := "00100101";

          when '&' => out_vect := "00100110";

          when ''' => out_vect := "00100111";

          when '(' => out_vect := "00101000";

          when ')' => out_vect := "00101001";

          when '*' => out_vect := "00101010";

          when '+' => out_vect := "00101011";

          when ',' => out_vect := "00101100";

          when '-' => out_vect := "00101101";

          when '.' => out_vect := "00101110";

          when '/' => out_vect := "00101111";

          when '0' => out_vect := "00110000";

          when '1' => out_vect := "00110001";

          when '2' => out_vect := "00110010";

          when '3' => out_vect := "00110011";

          when '4' => out_vect := "00110100";

          when '5' => out_vect := "00110101";

          when '6' => out_vect := "00110110";

          when '7' => out_vect := "00110111";

          when '8' => out_vect := "00111000";

          when '9' => out_vect := "00111001";

          when ':' => out_vect := "00111010";

          when ';' => out_vect := "00111011";

          when '<' => out_vect := "00111100";

          when '=' => out_vect := "00111101";

          when '>' => out_vect := "00111110";

          when '?' => out_vect := "00111111";

          when '@' => out_vect := "01000000";

          when 'A' => out_vect := "01000001";

          when 'B' => out_vect := "01000010";

          when 'C' => out_vect := "01000011";

          when 'D' => out_vect := "01000100";

          when 'E' => out_vect := "01000101";

          when 'F' => out_vect := "01000110";

          when 'G' => out_vect := "01000111";

          when 'H' => out_vect := "01001000";

          when 'I' => out_vect := "01001001";

          when 'J' => out_vect := "01001010";

          when 'K' => out_vect := "01001011";

          when 'L' => out_vect := "01001100";

          when 'M' => out_vect := "01001101";

          when 'N' => out_vect := "01001110";

          when 'O' => out_vect := "01001111";

          when 'P' => out_vect := "01010000";

          when 'Q' => out_vect := "01010001";

          when 'R' => out_vect := "01010010";

          when 'S' => out_vect := "01010011";

          when 'T' => out_vect := "01010100";

          when 'U' => out_vect := "01010101";

          when 'V' => out_vect := "01010110";

          when 'W' => out_vect := "01010111";

          when 'X' => out_vect := "01011000";

          when 'Y' => out_vect := "01011001";

          when 'Z' => out_vect := "01011010";

          when '[' => out_vect := "01011011";

          when '\' => out_vect := "01011100";

          when ']' => out_vect := "01011101";

          when '^' => out_vect := "01011110";

          when '_' => out_vect := "01011111";

          when '`' => out_vect := "01100000";

          when 'a' => out_vect := "01100001";

          when 'b' => out_vect := "01100010";

          when 'c' => out_vect := "01100011";

          when 'd' => out_vect := "01100100";

          when 'e' => out_vect := "01100101";

          when 'f' => out_vect := "01100110";

          when 'g' => out_vect := "01100111";

          when 'h' => out_vect := "01101000";

          when 'i' => out_vect := "01101001";

          when 'j' => out_vect := "01101010";

          when 'k' => out_vect := "01101011";

          when 'l' => out_vect := "01101100";

          when 'm' => out_vect := "01101101";

          when 'n' => out_vect := "01101110";

          when 'o' => out_vect := "01101111";

          when 'p' => out_vect := "01110000";

          when 'q' => out_vect := "01110001";

          when 'r' => out_vect := "01110010";

          when 's' => out_vect := "01110011";

          when 't' => out_vect := "01110100";

          when 'u' => out_vect := "01110101";

          when 'v' => out_vect := "01110110";

          when 'w' => out_vect := "01110111";

          when 'x' => out_vect := "01111000";

          when 'y' => out_vect := "01111001";

          when 'z' => out_vect := "01111010";

          when '{' => out_vect := "01111011";

          when '|' => out_vect := "01111100";

          when '}' => out_vect := "01111101";

          when '~' => out_vect := "01111110";

          when others =>

             out_vect := "00101010";

             --assert false report " illegal char to unsigned" severity note;

      end case;

      return out_vect;

     end;

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

--

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

    function hex_to_ascii(in_vector : std_logic_vector; nibbles : natural) return string is

    variable out_string : string(1 to nibbles);

    variable temp_in_vector : std_logic_vector(4*nibbles-1 downto 0);

    variable vector     : std_logic_vector(3 downto 0);

    begin

    temp_in_vector := in_vector(in_vector'length-1 downto in_vector'length-temp_in_vector'length);

        for i in 1 to nibbles loop

            vector := temp_in_vector((4*(nibbles-i)+3) downto 4*(nibbles-i));

            case vector is

                when "0000" => out_string(i) := '0';

                when "0001" => out_string(i) := '1';

                when "0010" => out_string(i) := '2';

                when "0011" => out_string(i) := '3';

                when "0100" => out_string(i) := '4';

                when "0101" => out_string(i) := '5';

                when "0110" => out_string(i) := '6';

                when "0111" => out_string(i) := '7';

                when "1000" => out_string(i) := '8';

                when "1001" => out_string(i) := '9';

                when "1010" => out_string(i) := 'A';

                when "1011" => out_string(i) := 'B';

                when "1100" => out_string(i) := 'C';

                when "1101" => out_string(i) := 'D';

                when "1110" => out_string(i) := 'E';

                when "1111" => out_string(i) := 'F';

                when others =>

                   out_string(i) := 'J';

                   assert false

                   report " illegal std_logic_vector to string"

                   severity note;

            end case;

        end loop;

        return out_string;

     end;

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

--

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

    function u2ascii(in_vector : unsigned; nibbles : natural) return string is

    variable out_string     : string(1 to nibbles);

    variable temp_in_vector : unsigned(4*nibbles-1 downto 0);

    variable vector         : unsigned(3 downto 0);

    begin

    temp_in_vector := in_vector(in_vector'length-1 downto in_vector'length-temp_in_vector'length);

        for i in 1 to nibbles loop

            vector := temp_in_vector((4*(nibbles-i)+3) downto 4*(nibbles-i));

            case vector is

                when "0000" => out_string(i) := '0';

                when "0001" => out_string(i) := '1';

                when "0010" => out_string(i) := '2';

                when "0011" => out_string(i) := '3';

                when "0100" => out_string(i) := '4';

                when "0101" => out_string(i) := '5';

                when "0110" => out_string(i) := '6';

                when "0111" => out_string(i) := '7';

                when "1000" => out_string(i) := '8';

                when "1001" => out_string(i) := '9';

                when "1010" => out_string(i) := 'A';

                when "1011" => out_string(i) := 'B';

                when "1100" => out_string(i) := 'C';

                when "1101" => out_string(i) := 'D';

                when "1110" => out_string(i) := 'E';

                when "1111" => out_string(i) := 'F';

                when others =>

                   out_string(i) := 'U';

                   assert false report " illegal unsigned to string" severity note;

            end case;

        end loop;

        return out_string;

     end;

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

--

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

    function hex_data_wrd(in_vector : std_logic_vector) return string is

    variable out_string : string(1 to 8);

    variable temp_in_vector : std_logic_vector(31 downto 0);

    variable vector     : std_logic_vector(3 downto 0);

    begin

    temp_in_vector := in_vector;

        for i in 1 to 8 loop

            vector := temp_in_vector((35-(4*i)) downto (32-(4*i)));

            case vector is

                when "0000" => out_string(i) := '0';

                when "0001" => out_string(i) := '1';

                when "0010" => out_string(i) := '2';

                when "0011" => out_string(i) := '3';

                when "0100" => out_string(i) := '4';

                when "0101" => out_string(i) := '5';

                when "0110" => out_string(i) := '6';

                when "0111" => out_string(i) := '7';

                when "1000" => out_string(i) := '8';

                when "1001" => out_string(i) := '9';

                when "1010" => out_string(i) := 'A';

                when "1011" => out_string(i) := 'B';

                when "1100" => out_string(i) := 'C';

                when "1101" => out_string(i) := 'D';

                when "1110" => out_string(i) := 'E';

                when "1111" => out_string(i) := 'F';

                when others =>

                   out_string(i) := 'J';

                   assert false

                   report " illegal std_logic_vector to string"

                   severity note;

            end case;

        end loop;

        return out_string;

     end;

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

--

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

    function hex_data_dblwrd(in_vector : std_logic_vector) return string is

    variable out_string : string(1 to 16);

    variable temp_in_vector : std_logic_vector(63 downto 0);

    variable vector     : std_logic_vector(3 downto 0);

    begin

    temp_in_vector := in_vector;

        for i in 1 to 16 loop

            vector := temp_in_vector((67-(4*i)) downto (64-(4*i)));

            case vector is

                when "0000" => out_string(i) := '0';

                when "0001" => out_string(i) := '1';

                when "0010" => out_string(i) := '2';

                when "0011" => out_string(i) := '3';

                when "0100" => out_string(i) := '4';

                when "0101" => out_string(i) := '5';

                when "0110" => out_string(i) := '6';

                when "0111" => out_string(i) := '7';

                when "1000" => out_string(i) := '8';

                when "1001" => out_string(i) := '9';

                when "1010" => out_string(i) := 'A';

                when "1011" => out_string(i) := 'B';

                when "1100" => out_string(i) := 'C';

                when "1101" => out_string(i) := 'D';

                when "1110" => out_string(i) := 'E';

                when "1111" => out_string(i) := 'F';

                when others =>

                   out_string(i) := 'J';

                   assert false

                   report " illegal std_logic_vector to string"

                   severity note;

            end case;

        end loop;

        return out_string;

     end;

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

--

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

    function hex_data_dblwrdz(in_vector : std_logic_vector) return string is

    variable out_string : string(1 to 16);

    variable temp_in_vector : std_logic_vector(63 downto 0);

    variable vector     : std_logic_vector(3 downto 0);

    begin

    temp_in_vector := in_vector;

        for i in 1 to 16 loop

            vector := temp_in_vector((67-(4*i)) downto (64-(4*i)));

            case vector is

                when "0000" => out_string(i) := '0';

                when "0001" => out_string(i) := '1';

                when "0010" => out_string(i) := '2';

                when "0011" => out_string(i) := '3';

                when "0100" => out_string(i) := '4';

                when "0101" => out_string(i) := '5';

                when "0110" => out_string(i) := '6';

                when "0111" => out_string(i) := '7';

                when "1000" => out_string(i) := '8';

                when "1001" => out_string(i) := '9';

                when "1010" => out_string(i) := 'A';

                when "1011" => out_string(i) := 'B';

                when "1100" => out_string(i) := 'C';

                when "1101" => out_string(i) := 'D';

                when "1110" => out_string(i) := 'E';

                when "1111" => out_string(i) := 'F';

                when "ZZZZ" => out_string(i) := 'Z';

                when others =>

                   out_string(i) := 'J';

                   assert false

                   report " illegal std_logic_vector to string"

                   severity note;

            end case;

        end loop;

        return out_string;

     end;

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

--

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

function str2u2(s: string) return unsigned is

  variable uv: unsigned(8*s'high-1 downto 0);

  variable k: integer;

begin

   k := s'high-s'low;

  for i in s'range loop

--     uv(8*k+7 downto 8*k) := unsigned(chartobyte(s(i)));

     uv(8*k+7 downto 8*k) := asciichar2u2(s(i));

     k      := k - 1;

  end loop;

  return uv;

end str2u2;

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

--

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

    -- returns true if the character is a valid hexadecimal character.

    function is_hex(c : character) return boolean is

    begin

      case c is

        when '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' |

             'A' | 'B' | 'C' | 'D' | 'E' | 'F' | 'a' | 'b' | 'c' | 'd' |

             'e' | 'f' =>

          return(true);

        when others =>

          return(false);

      end case;

    end is_hex;

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

--

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

    -- returns true if the character is a valid hexadecimal character.

    function is_std_logic(c : character) return boolean is

    begin

      case c is

        when '0' | '1' | 'u' | 'U' | 'x' | 'X' | 'z' | 'Z' =>

          return(true);

        when others =>

          return(false);

      end case;

    end is_std_logic;

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

--