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[/] [spi_slave/] [trunk/] [bench/] [vhdl/] [images-body.vhd] - Rev 38
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-------------------------------------------------------------------------- -- -- Copyright (C) 1993, Peter J. Ashenden -- Mail: Dept. Computer Science -- University of Adelaide, SA 5005, Australia -- e-mail: petera@cs.adelaide.edu.au -- -- This program is free software; you can redistribute it and/or modify -- it under the terms of the GNU General Public License as published by -- the Free Software Foundation; either version 1, or (at your option) -- any later version. -- -- This program is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -- GNU General Public License for more details. -- -- You should have received a copy of the GNU General Public License -- along with this program; if not, write to the Free Software -- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. -- -------------------------------------------------------------------------- -- -- $RCSfile: images-body.vhd,v $ $Revision: 1.1 $ $Date: 2007-11-30 20:22:01 $ -- -------------------------------------------------------------------------- -- -- Images package body. -- -- Functions that return the string image of values. -- Each image is a correctly formed literal according to the -- rules of VHDL-93. -- -------------------------------------------------------------------------- library ieee; use ieee.std_logic_1164.all; package images is function image ( constant bv : std_logic_vector) return string; end images; package body images is -- Image of bit vector as binary bit string literal -- (in the format B"...") -- Length of result is bv'length + 3 function image (bv : in bit_vector) return string is alias bv_norm : bit_vector(1 to bv'length) is bv; variable result : string(1 to bv'length + 3); begin result(1) := 'B'; result(2) := '"'; for index in bv_norm'range loop if bv_norm(index) = '0' then result(index + 2) := '0'; else result(index + 2) := '1'; end if; end loop; result(bv'length + 3) := '"'; return result; end image; ------------------------------------------------------------------------------- -- Image of bit vector as binary bit string literal -- (in the format B"...") -- Length of result is bv'length + 3 function image (bv : in std_logic_vector) return string is alias bv_norm : std_logic_vector(1 to bv'length) is bv; variable result : string(1 to bv'length + 3); begin result(1) := 'B'; result(2) := '"'; for index in bv_norm'range loop if bv_norm(index) = '0' then result(index + 2) := '0'; else result(index + 2) := '1'; end if; end loop; result(bv'length + 3) := '"'; return result; end image; ---------------------------------------------------------------- -- Image of bit vector as octal bit string literal -- (in the format O"...") -- Length of result is (bv'length+2)/3 + 3 function image_octal (bv : in bit_vector) return string is constant nr_digits : natural := (bv'length + 2) / 3; variable result : string(1 to nr_digits + 3); variable bits : bit_vector(0 to 3*nr_digits - 1) := (others => '0'); variable three_bits : bit_vector(0 to 2); variable digit : character; begin result(1) := 'O'; result(2) := '"'; bits(bits'right - bv'length + 1 to bits'right) := bv; for index in 0 to nr_digits - 1 loop three_bits := bits(3*index to 3*index + 2); case three_bits is when b"000" => digit := '0'; when b"001" => digit := '1'; when b"010" => digit := '2'; when b"011" => digit := '3'; when b"100" => digit := '4'; when b"101" => digit := '5'; when b"110" => digit := '6'; when b"111" => digit := '7'; end case; result(index + 3) := digit; end loop; result(nr_digits + 3) := '"'; return result; end image_octal; ---------------------------------------------------------------- -- Image of bit vector as hex bit string literal -- (in the format X"...") -- Length of result is (bv'length+3)/4 + 3 function image_hex (bv : in bit_vector) return string is constant nr_digits : natural := (bv'length + 3) / 4; variable result : string(1 to nr_digits + 3); variable bits : bit_vector(0 to 4*nr_digits - 1) := (others => '0'); variable four_bits : bit_vector(0 to 3); variable digit : character; begin result(1) := 'X'; result(2) := '"'; bits(bits'right - bv'length + 1 to bits'right) := bv; for index in 0 to nr_digits - 1 loop four_bits := bits(4*index to 4*index + 3); case four_bits is when b"0000" => digit := '0'; when b"0001" => digit := '1'; when b"0010" => digit := '2'; when b"0011" => digit := '3'; when b"0100" => digit := '4'; when b"0101" => digit := '5'; when b"0110" => digit := '6'; when b"0111" => digit := '7'; when b"1000" => digit := '8'; when b"1001" => digit := '9'; when b"1010" => digit := 'A'; when b"1011" => digit := 'B'; when b"1100" => digit := 'C'; when b"1101" => digit := 'D'; when b"1110" => digit := 'E'; when b"1111" => digit := 'F'; end case; result(index + 3) := digit; end loop; result(nr_digits + 3) := '"'; return result; end image_hex; end images;
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