1/*
2 * Copyright (c) 2013 ARM Limited
3 * Copyright (c) 2013 Cornell University
4 * All rights reserved
5 *
6 * The license below extends only to copyright in the software and shall
7 * not be construed as granting a license to any other intellectual
8 * property including but not limited to intellectual property relating
9 * to a hardware implementation of the functionality of the software
10 * licensed hereunder. You may use the software subject to the license
11 * terms below provided that you ensure that this notice is replicated
12 * unmodified and in its entirety in all distributions of the software,
13 * modified or unmodified, in source code or in binary form.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions are
17 * met: redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer;
19 * redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution;
22 * neither the name of the copyright holders nor the names of its
23 * contributors may be used to endorse or promote products derived from
24 * this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
29 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
30 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
31 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
32 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
36 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * Authors: Vasileios Spiliopoulos
39 * Akash Bagdia
40 * Andreas Hansson
41 * Christopher Torng
42 */
43
44#include "debug/ClockDomain.hh"
45#include "params/ClockDomain.hh"
46#include "params/DerivedClockDomain.hh"
47#include "params/SrcClockDomain.hh"
48#include "sim/clock_domain.hh"
49#include "sim/voltage_domain.hh"
50#include "sim/clocked_object.hh"
51
52double
53ClockDomain::voltage() const
54{
55 return _voltageDomain->voltage();
56}
57
58SrcClockDomain::SrcClockDomain(const Params *p) :
59 ClockDomain(p, p->voltage_domain)
60{
61 clockPeriod(p->clock);
62}
63
64void
65SrcClockDomain::clockPeriod(Tick clock_period)
66{
67 if (clock_period == 0) {
68 fatal("%s has a clock period of zero\n", name());
69 }
70
71 // Align all members to the current tick
72 for (auto m = members.begin(); m != members.end(); ++m) {
73 (*m)->updateClockPeriod();
74 }
75
76 _clockPeriod = clock_period;
77
78 DPRINTF(ClockDomain,
79 "Setting clock period to %d ticks for source clock %s\n",
80 _clockPeriod, name());
81
82 // inform any derived clocks they need to updated their period
83 for (auto c = children.begin(); c != children.end(); ++c) {
84 (*c)->updateClockPeriod();
85 }
86}
87
88SrcClockDomain *
89SrcClockDomainParams::create()
90{
91 return new SrcClockDomain(this);
92}
93
94DerivedClockDomain::DerivedClockDomain(const Params *p) :
95 ClockDomain(p, p->clk_domain->voltageDomain()),
96 parent(*p->clk_domain),
97 clockDivider(p->clk_divider)
98{
99 // Ensure that clock divider setting works as frequency divider and never
100 // work as frequency multiplier
101 if (clockDivider < 1) {
102 fatal("Clock divider param cannot be less than 1");
103 }
104
105 // let the parent keep track of this derived domain so that it can
106 // propagate changes
107 parent.addDerivedDomain(this);
108
109 // update our clock period based on the parents clock
110 updateClockPeriod();
111}
112
113void
114DerivedClockDomain::updateClockPeriod()
115{
116 // Align all members to the current tick
117 for (auto m = members.begin(); m != members.end(); ++m) {
118 (*m)->updateClockPeriod();
119 }
120
121 // recalculate the clock period, relying on the fact that changes
122 // propagate downwards in the tree
123 _clockPeriod = parent.clockPeriod() * clockDivider;
124
125 DPRINTF(ClockDomain,
126 "Setting clock period to %d ticks for derived clock %s\n",
127 _clockPeriod, name());
128
129 // inform any derived clocks
130 for (auto c = children.begin(); c != children.end(); ++c) {
131 (*c)->updateClockPeriod();
132 }
133}
134
135DerivedClockDomain *
136DerivedClockDomainParams::create()
137{
138 return new DerivedClockDomain(this);
139}