diff options
Diffstat (limited to 'testsuite/vests/vhdl-93/ashenden/compliant/bv_images_body.vhd')
| -rw-r--r-- | testsuite/vests/vhdl-93/ashenden/compliant/bv_images_body.vhd | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/testsuite/vests/vhdl-93/ashenden/compliant/bv_images_body.vhd b/testsuite/vests/vhdl-93/ashenden/compliant/bv_images_body.vhd new file mode 100644 index 000000000..285bb557f --- /dev/null +++ b/testsuite/vests/vhdl-93/ashenden/compliant/bv_images_body.vhd @@ -0,0 +1,168 @@ + +-- Copyright (C) 1996 Morgan Kaufmann Publishers, Inc + +-- This file is part of VESTs (Vhdl tESTs). + +-- VESTs 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 2 of the License, or (at +-- your option) any later version. + +-- VESTs 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 VESTs; if not, write to the Free Software Foundation, +-- Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + +-- --------------------------------------------------------------------- +-- +-- $Id: bv_images_body.vhd,v 1.3 2001-10-26 16:29:33 paw Exp $ +-- $Revision: 1.3 $ +-- +-- --------------------------------------------------------------------- + +-------------------------------------------------------------------------- +-- +-- bv_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. +-- +-------------------------------------------------------------------------- + +package body bv_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 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 bv_images; |