sc_clock.cc revision 13200:06d1460c28ad 
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_main.hh"
40#include "systemc/ext/core/sc_module.hh" // for sc_gen_unique_name
41
42namespace sc_gem5
43{
44
45class ClockTick : public ScEvent
46{
47  private:
48    ::sc_core::sc_clock *clock;
49    ::sc_core::sc_time _period;
50    std::string name;
51    Process *p;
52    ProcessMemberFuncWrapper<::sc_core::sc_clock> funcWrapper;
53
54  public:
55    ClockTick(::sc_core::sc_clock *clock, bool to,
56            ::sc_core::sc_time _period) :
57        ScEvent([this]() { tick(); }),
58        clock(clock), _period(_period), name(clock->basename()), p(nullptr),
59        funcWrapper(clock, to ? &::sc_core::sc_clock::tickUp :
60                                &::sc_core::sc_clock::tickDown)
61    {
62        name += std::string(to ? "_posedge_action" : "_negedge_action");
63        name = ::sc_core::sc_gen_unique_name(name.c_str());
64    }
65
66    void
67    createProcess()
68    {
69        p = new Method(name.c_str(), &funcWrapper, true);
70        p->dontInitialize(true);
71        scheduler.reg(p);
72    }
73
74    ~ClockTick()
75    {
76        if (scheduled())
77            scheduler.deschedule(this);
78        if (p)
79            p->popListNode();
80    }
81
82    void
83    tick()
84    {
85        scheduler.schedule(this, _period);
86        p->ready();
87    }
88};
89
90};
91
92namespace sc_core
93{
94
95sc_clock::sc_clock() :
96    sc_clock(sc_gen_unique_name("clock"), sc_time(1.0, SC_NS),
97            0.5, SC_ZERO_TIME, true)
98{}
99
100sc_clock::sc_clock(const char *name) :
101    sc_clock(name, sc_time(1.0, SC_NS), 0.5, SC_ZERO_TIME, true)
102{}
103
104sc_clock::sc_clock(const char *name, const sc_time &period,
105                   double duty_cycle, const sc_time &start_time,
106                   bool posedge_first) :
107    sc_interface(), sc_signal<bool>(name, posedge_first ? false : true),
108    _period(period), _dutyCycle(duty_cycle), _startTime(start_time),
109    _posedgeFirst(posedge_first)
110{
111    _gem5UpEdge = new ::sc_gem5::ClockTick(this, true, period);
112    _gem5DownEdge = new ::sc_gem5::ClockTick(this, false, period);
113}
114
115sc_clock::sc_clock(const char *name, double period_v, sc_time_unit period_tu,
116                   double duty_cycle) :
117    sc_clock(name, sc_time(period_v, period_tu), duty_cycle, SC_ZERO_TIME,
118            true)
119{}
120
121sc_clock::sc_clock(const char *name, double period_v, sc_time_unit period_tu,
122                   double duty_cycle, double start_time_v,
123                   sc_time_unit start_time_tu, bool posedge_first) :
124    sc_clock(name, sc_time(period_v, period_tu), duty_cycle,
125            sc_time(start_time_v, start_time_tu), posedge_first)
126{}
127
128sc_clock::sc_clock(const char *name, double period, double duty_cycle,
129                   double start_time, bool posedge_first) :
130    sc_clock(name, sc_time(period, true), duty_cycle,
131            sc_time(start_time, true), posedge_first)
132{}
133
134sc_clock::~sc_clock()
135{
136    if (_gem5UpEdge->scheduled())
137        ::sc_gem5::scheduler.deschedule(_gem5UpEdge);
138    if (_gem5DownEdge->scheduled())
139        ::sc_gem5::scheduler.deschedule(_gem5DownEdge);
140    delete _gem5UpEdge;
141    delete _gem5DownEdge;
142}
143
144void
145sc_clock::write(const bool &)
146{
147    panic("write() called on sc_clock.");
148}
149
150const sc_time &sc_clock::period() const { return _period; }
151double sc_clock::duty_cycle() const { return _dutyCycle; }
152const sc_time &sc_clock::start_time() const { return _startTime; }
153bool sc_clock::posedge_first() const { return _posedgeFirst; }
154
155const sc_time &
156sc_clock::time_stamp()
157{
158    return sc_time_stamp();
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