sc_clock.cc revision 13324:c8b709468e61 
1/*
2 * Copyright 2018 Google, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution;
11 * neither the name of the copyright holders nor the names of its
12 * contributors may be used to endorse or promote products derived from
13 * this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Gabe Black
28 */
29
30#include "base/logging.hh"
31#include "base/types.hh"
32#include "sim/core.hh"
33#include "sim/eventq.hh"
34#include "systemc/core/kernel.hh"
35#include "systemc/core/process_types.hh"
36#include "systemc/core/sched_event.hh"
37#include "systemc/core/scheduler.hh"
38#include "systemc/ext/channel/messages.hh"
39#include "systemc/ext/channel/sc_clock.hh"
40#include "systemc/ext/core/sc_main.hh"
41#include "systemc/ext/core/sc_module.hh" // for sc_gen_unique_name
42#include "systemc/ext/utils/sc_report_handler.hh"
43
44namespace sc_gem5
45{
46
47class ClockTick : public ScEvent
48{
49  private:
50    ::sc_core::sc_clock *clock;
51    ::sc_core::sc_time _period;
52    std::string name;
53    Process *p;
54    ProcessMemberFuncWrapper<::sc_core::sc_clock> funcWrapper;
55
56  public:
57    ClockTick(::sc_core::sc_clock *clock, bool to,
58            ::sc_core::sc_time _period) :
59        ScEvent([this]() { tick(); }),
60        clock(clock), _period(_period), name(clock->basename()), p(nullptr),
61        funcWrapper(clock, to ? &::sc_core::sc_clock::tickUp :
62                                &::sc_core::sc_clock::tickDown)
63    {
64        name += std::string(to ? "_posedge_action" : "_negedge_action");
65        name = ::sc_core::sc_gen_unique_name(name.c_str());
66    }
67
68    void
69    createProcess()
70    {
71        p = new Method(name.c_str(), &funcWrapper, true);
72        p->dontInitialize(true);
73        scheduler.reg(p);
74    }
75
76    ~ClockTick()
77    {
78        if (scheduled())
79            scheduler.deschedule(this);
80        if (p)
81            p->popListNode();
82    }
83
84    void
85    tick()
86    {
87        scheduler.schedule(this, _period);
88        p->ready();
89    }
90};
91
92};
93
94namespace sc_core
95{
96
97sc_clock::sc_clock() :
98    sc_clock(sc_gen_unique_name("clock"), sc_time(1.0, SC_NS),
99            0.5, SC_ZERO_TIME, true)
100{}
101
102sc_clock::sc_clock(const char *name) :
103    sc_clock(name, sc_time(1.0, SC_NS), 0.5, SC_ZERO_TIME, true)
104{}
105
106sc_clock::sc_clock(const char *name, const sc_time &period,
107                   double duty_cycle, const sc_time &start_time,
108                   bool posedge_first) :
109    sc_interface(), sc_signal<bool>(name, posedge_first ? false : true),
110    _period(period), _dutyCycle(duty_cycle), _startTime(start_time),
111    _posedgeFirst(posedge_first)
112{
113    if (period == SC_ZERO_TIME) {
114        std::string msg =
115            "increase the period: clock '" +
116            std::string(name) + "'";
117        SC_REPORT_ERROR(SC_ID_CLOCK_PERIOD_ZERO_, msg.c_str());
118    }
119
120    if (duty_cycle * period == SC_ZERO_TIME) {
121        std::string msg =
122            "increase the period or increase the duty cycle: clock '" +
123            std::string(name) + "'";
124        SC_REPORT_ERROR(SC_ID_CLOCK_HIGH_TIME_ZERO_, msg.c_str());
125    }
126
127    if (duty_cycle * period == period) {
128        std::string msg =
129            "increase the period or decrease the duty cycle: clock '" +
130            std::string(name) + "'";
131        SC_REPORT_ERROR(SC_ID_CLOCK_LOW_TIME_ZERO_, msg.c_str());
132    }
133
134    _gem5UpEdge = new ::sc_gem5::ClockTick(this, true, period);
135    _gem5DownEdge = new ::sc_gem5::ClockTick(this, false, period);
136}
137
138sc_clock::sc_clock(const char *name, double period_v, sc_time_unit period_tu,
139                   double duty_cycle) :
140    sc_clock(name, sc_time(period_v, period_tu), duty_cycle, SC_ZERO_TIME,
141            true)
142{}
143
144sc_clock::sc_clock(const char *name, double period_v, sc_time_unit period_tu,
145                   double duty_cycle, double start_time_v,
146                   sc_time_unit start_time_tu, bool posedge_first) :
147    sc_clock(name, sc_time(period_v, period_tu), duty_cycle,
148            sc_time(start_time_v, start_time_tu), posedge_first)
149{}
150
151sc_clock::sc_clock(const char *name, double period, double duty_cycle,
152                   double start_time, bool posedge_first) :
153    sc_clock(name, sc_time(period, true), duty_cycle,
154            sc_time(start_time, true), posedge_first)
155{}
156
157sc_clock::~sc_clock()
158{
159    if (_gem5UpEdge->scheduled())
160        ::sc_gem5::scheduler.deschedule(_gem5UpEdge);
161    if (_gem5DownEdge->scheduled())
162        ::sc_gem5::scheduler.deschedule(_gem5DownEdge);
163    delete _gem5UpEdge;
164    delete _gem5DownEdge;
165}
166
167void
168sc_clock::write(const bool &)
169{
170    panic("write() called on sc_clock.");
171}
172
173const sc_time &sc_clock::period() const { return _period; }
174double sc_clock::duty_cycle() const { return _dutyCycle; }
175const sc_time &sc_clock::start_time() const { return _startTime; }
176bool sc_clock::posedge_first() const { return _posedgeFirst; }
177
178const sc_time &
179sc_clock::time_stamp()
180{
181    return sc_time_stamp();
182}
183
184void
185sc_clock::before_end_of_elaboration()
186{
187    _gem5UpEdge->createProcess();
188    _gem5DownEdge->createProcess();
189    if (_posedgeFirst) {
190        ::sc_gem5::scheduler.schedule(_gem5UpEdge, _startTime);
191        ::sc_gem5::scheduler.schedule(_gem5DownEdge,
192                _startTime + _period * _dutyCycle);
193    } else {
194        ::sc_gem5::scheduler.schedule(_gem5DownEdge, _startTime);
195        ::sc_gem5::scheduler.schedule(_gem5UpEdge,
196                _startTime + _period * (1.0 - _dutyCycle));
197    }
198}
199
200} // namespace sc_core
201