sc_clock.cc revision 13194 
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/sc_clock.hh"
39#include "systemc/ext/core/sc_module.hh" // for sc_gen_unique_name
40
41namespace sc_gem5
42{
43
44class ClockTick : public ScEvent
45{
46  private:
47    ::sc_core::sc_clock *clock;
48    ::sc_core::sc_time _period;
49    std::string name;
50    Process *p;
51    ProcessMemberFuncWrapper<::sc_core::sc_clock> funcWrapper;
52
53  public:
54    ClockTick(::sc_core::sc_clock *clock, bool to,
55            ::sc_core::sc_time _period) :
56        ScEvent([this]() { tick(); }),
57        clock(clock), _period(_period), name(clock->basename()), p(nullptr),
58        funcWrapper(clock, to ? &::sc_core::sc_clock::tickUp :
59                                &::sc_core::sc_clock::tickDown)
60    {
61        name += std::string(to ? "_posedge_action" : "_negedge_action");
62        name = ::sc_core::sc_gen_unique_name(name.c_str());
63    }
64
65    void
66    createProcess()
67    {
68        p = new Method(name.c_str(), &funcWrapper, true);
69        p->dontInitialize(true);
70        scheduler.reg(p);
71    }
72
73    ~ClockTick()
74    {
75        if (scheduled())
76            scheduler.deschedule(this);
77        if (p)
78            p->popListNode();
79    }
80
81    void
82    tick()
83    {
84        scheduler.schedule(this, _period);
85        p->ready();
86    }
87};
88
89};
90
91namespace sc_core
92{
93
94sc_clock::sc_clock() :
95    sc_clock(sc_gen_unique_name("clock"), sc_time(1.0, SC_NS),
96            0.5, SC_ZERO_TIME, true)
97{}
98
99sc_clock::sc_clock(const char *name) :
100    sc_clock(name, sc_time(1.0, SC_NS), 0.5, SC_ZERO_TIME, true)
101{}
102
103sc_clock::sc_clock(const char *name, const sc_time &period,
104                   double duty_cycle, const sc_time &start_time,
105                   bool posedge_first) :
106    sc_interface(), sc_signal<bool>(name, posedge_first ? false : true),
107    _period(period), _dutyCycle(duty_cycle), _startTime(start_time),
108    _posedgeFirst(posedge_first)
109{
110    _gem5UpEdge = new ::sc_gem5::ClockTick(this, true, period);
111    _gem5DownEdge = new ::sc_gem5::ClockTick(this, false, period);
112}
113
114sc_clock::sc_clock(const char *name, double period_v, sc_time_unit period_tu,
115                   double duty_cycle) :
116    sc_clock(name, sc_time(period_v, period_tu), duty_cycle, SC_ZERO_TIME,
117            true)
118{}
119
120sc_clock::sc_clock(const char *name, double period_v, sc_time_unit period_tu,
121                   double duty_cycle, double start_time_v,
122                   sc_time_unit start_time_tu, bool posedge_first) :
123    sc_clock(name, sc_time(period_v, period_tu), duty_cycle,
124            sc_time(start_time_v, start_time_tu), posedge_first)
125{}
126
127sc_clock::sc_clock(const char *name, double period, double duty_cycle,
128                   double start_time, bool posedge_first) :
129    sc_clock(name, sc_time(period, true), duty_cycle,
130            sc_time(start_time, true), posedge_first)
131{}
132
133sc_clock::~sc_clock()
134{
135    if (_gem5UpEdge->scheduled())
136        ::sc_gem5::scheduler.deschedule(_gem5UpEdge);
137    if (_gem5DownEdge->scheduled())
138        ::sc_gem5::scheduler.deschedule(_gem5DownEdge);
139    delete _gem5UpEdge;
140    delete _gem5DownEdge;
141}
142
143void
144sc_clock::write(const bool &)
145{
146    panic("write() called on sc_clock.");
147}
148
149const sc_time &sc_clock::period() const { return _period; }
150double sc_clock::duty_cycle() const { return _dutyCycle; }
151const sc_time &sc_clock::start_time() const { return _startTime; }
152bool sc_clock::posedge_first() const { return _posedgeFirst; }
153
154const sc_time &
155sc_clock::time_stamp()
156{
157    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
158    return *(const sc_time *)nullptr;
159}
160
161void
162sc_clock::before_end_of_elaboration()
163{
164    _gem5UpEdge->createProcess();
165    _gem5DownEdge->createProcess();
166    if (_posedgeFirst) {
167        ::sc_gem5::scheduler.schedule(_gem5UpEdge, _startTime);
168        ::sc_gem5::scheduler.schedule(_gem5DownEdge,
169                _startTime + _period * _dutyCycle);
170    } else {
171        ::sc_gem5::scheduler.schedule(_gem5DownEdge, _startTime);
172        ::sc_gem5::scheduler.schedule(_gem5UpEdge,
173                _startTime + _period * (1.0 - _dutyCycle));
174    }
175}
176
177} // namespace sc_core
178