Project

General

Profile

Download (7.29 KB) Statistics
| Branch: | Tag: | Revision:
1

    
2
-- Copyright (C) 1996 Morgan Kaufmann Publishers, Inc
3

    
4
-- This file is part of VESTs (Vhdl tESTs).
5

    
6
-- VESTs is free software; you can redistribute it and/or modify it
7
-- under the terms of the GNU General Public License as published by the
8
-- Free Software Foundation; either version 2 of the License, or (at
9
-- your option) any later version. 
10

    
11
-- VESTs is distributed in the hope that it will be useful, but WITHOUT
12
-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13
-- FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14
-- for more details. 
15

    
16
-- You should have received a copy of the GNU General Public License
17
-- along with VESTs; if not, write to the Free Software Foundation,
18
-- Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
19

    
20
-- ---------------------------------------------------------------------
21
--
22
-- $Id: ch_20_ch_20_06.vhd,v 1.2 2001-10-26 16:29:36 paw Exp $
23
-- $Revision: 1.2 $
24
--
25
-- ---------------------------------------------------------------------
26

    
27
entity ch_20_06 is
28

    
29
end entity ch_20_06;
30

    
31

    
32
----------------------------------------------------------------
33

    
34
use std.textio.all;
35

    
36
architecture test of ch_20_06 is
37

    
38
  subtype encoding_type is bit_vector(1 downto 0);
39
  attribute encoding : encoding_type;
40

    
41
begin
42

    
43

    
44
  process1 : process is
45

    
46
                       -- code from book:
47

    
48
                       type controller_state is (idle, active, fail_safe);
49
                     type load_level is (idle, busy, overloaded);
50

    
51
                     attribute encoding of idle [ return controller_state ] : literal is b"00";
52
                                                                                         attribute encoding of active [ return controller_state ] : literal is b"01";
53
                                                                                                                                                               attribute encoding of fail_safe [ return controller_state ] : literal is b"10";
54

    
55
                                                                                                                                                                                                                                        -- end of code from book
56

    
57
                                                                                                                                                                                                                                        variable L : line;
58

    
59
                                                                                                                                                               begin
60
                                                                                                                                                                 write(L, string'("process1"));
61
                                                                                                                                                                 writeline(output, L);
62
                                                                                                                                                                 write(L, idle [ return controller_state ] ' encoding);
63
                                                                                                                                                                 writeline(output, L);
64
                                                                                                                                                                 write(L, active [ return controller_state ] ' encoding);
65
                                                                                                                                                                 writeline(output, L);
66
                                                                                                                                                                 write(L, fail_safe [ return controller_state ] ' encoding);
67
                                                                                                                                                                 writeline(output, L);
68
                                                                                                                                                                 wait;
69
                                                                                                                                                               end process process1;
70

    
71

    
72
                                                                                                                                                               process2 : process is
73

    
74
                                                                                                                                                                                    type controller_state is (idle, active, fail_safe);
75
                                                                                                                                                                                  type load_level is (idle, busy, overloaded);
76

    
77
                                                                                                                                                                                  attribute encoding of idle : literal is b"11";
78

    
79
                                                                                                                                                                                  variable L : line;
80

    
81
                                                                                                                                                               begin
82
                                                                                                                                                                 write(L, string'("process2"));
83
                                                                                                                                                                 writeline(output, L);
84
                                                                                                                                                                 write(L, idle [ return controller_state ] ' encoding);
85
                                                                                                                                                                 writeline(output, L);
86
                                                                                                                                                                 write(L, idle [ return load_level ] ' encoding);
87
                                                                                                                                                                 writeline(output, L);
88
                                                                                                                                                                 wait;
89
                                                                                                                                                               end process process2;
90

    
91

    
92
                                                                                         end architecture test;
(160-160/171)