1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
-- 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: ch_16_fg_16_15.vhd,v 1.2 2001-10-26 16:29:36 paw Exp $
-- $Revision: 1.2 $
--
-- ---------------------------------------------------------------------
entity circuit is
generic ( inpad_delay, outpad_delay : delay_length );
port ( in1, in2, in3 : in bit; out1, out2 : out bit );
end entity circuit;
--------------------------------------------------
architecture with_pad_delays of circuit is
component subcircuit is
port ( a, b : in bit; y1, y2 : out bit );
end component subcircuit;
signal delayed_in1, delayed_in2, delayed_in3 : bit;
signal undelayed_out1, undelayed_out2 : bit;
begin
input_delays : block is
begin
delayed_in1 <= in1 after inpad_delay;
delayed_in2 <= in2 after inpad_delay;
delayed_in3 <= in3 after inpad_delay;
end block input_delays;
functionality : block is
signal intermediate : bit;
begin
cell1 : component subcircuit
port map ( delayed_in1, delayed_in2, undelayed_out1, intermediate );
cell2 : component subcircuit
port map ( intermediate, delayed_in3, undelayed_out2, open );
end block functionality;
output_delays : block is
begin
out1 <= undelayed_out1 after outpad_delay;
out2 <= undelayed_out2 after outpad_delay;
end block output_delays;
end architecture with_pad_delays;
|
