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
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*
* Copyright (c) 2013 ARM Limited
* Copyright (c) 2013 Cornell University
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Vasileios Spiliopoulos
* Akash Bagdia
* Christopher Torng
*/
/**
* @file
* ClockDomain declarations.
*/
#ifndef __SIM_CLOCK_DOMAIN_HH__
#define __SIM_CLOCK_DOMAIN_HH__
#include <algorithm>
#include "base/statistics.hh"
#include "params/ClockDomain.hh"
#include "params/DerivedClockDomain.hh"
#include "params/SrcClockDomain.hh"
#include "sim/sim_object.hh"
/**
* Forward declaration
*/
class DerivedClockDomain;
class VoltageDomain;
class ClockedObject;
/**
* The ClockDomain provides clock to group of clocked objects bundled
* under the same clock domain. The clock domains, in turn, are
* grouped into voltage domains. The clock domains provide support for
* a hierarchial structure with source and derived domains.
*/
class ClockDomain : public SimObject
{
protected:
/**
* Pre-computed clock period in ticks. This is populated by the
* inheriting classes based on how their period is determined.
*/
Tick _clockPeriod;
/**
* Voltage domain this clock domain belongs to
*/
VoltageDomain *_voltageDomain;
/**
* Pointers to potential derived clock domains so we can propagate
* changes.
*/
std::vector<DerivedClockDomain*> children;
/**
* Pointers to members of this clock domain, so that when the clock
* period changes, we can update each member's tick.
*/
std::vector<ClockedObject*> members;
public:
typedef ClockDomainParams Params;
ClockDomain(const Params *p, VoltageDomain *voltage_domain) :
SimObject(p),
_clockPeriod(0),
_voltageDomain(voltage_domain) {}
/**
* Get the clock period.
*
* @return Clock period in ticks
*/
inline Tick clockPeriod() const { return _clockPeriod; }
/**
* Register a ClockedObject to this ClockDomain.
*
* @param ClockedObject to add as a member
*/
void registerWithClockDomain(ClockedObject *c)
{
assert(c != NULL);
assert(std::find(members.begin(), members.end(), c) == members.end());
members.push_back(c);
}
/**
* Get the voltage domain.
*
* @return Voltage domain this clock domain belongs to
*/
inline VoltageDomain *voltageDomain() const { return _voltageDomain; }
/**
* Get the current voltage this clock domain operates at.
*
* @return Voltage applied to the clock domain
*/
inline double voltage() const;
/**
* Add a derived domain.
*
* @param Derived domain to add as a child
*/
void addDerivedDomain(DerivedClockDomain *clock_domain)
{ children.push_back(clock_domain); }
};
/**
* The source clock domains provides the notion of a clock domain that is
* connected to a tunable clock source. It maintains the clock period and
* provides methods for setting/getting the clock.
*/
class SrcClockDomain : public ClockDomain
{
public:
typedef SrcClockDomainParams Params;
SrcClockDomain(const Params *p);
/**
* Set new clock value
* @param clock The new clock period in ticks
*/
void clockPeriod(Tick clock_period);
// Explicitly import the otherwise hidden clockPeriod
using ClockDomain::clockPeriod;
};
/**
* The derived clock domains provides the notion of a clock domain
* that is connected to a parent clock domain that can either be a
* source clock domain or a derived clock domain. It maintains the
* clock divider and provides methods for getting the clock.
*/
class DerivedClockDomain: public ClockDomain
{
public:
typedef DerivedClockDomainParams Params;
DerivedClockDomain(const Params *p);
/**
* Called by the parent clock domain to propagate changes. This
* also involves propagating the change further to any children of
* the derived domain itself.
*/
void updateClockPeriod();
private:
/**
* Reference to the parent clock domain this clock domain derives
* its clock period from
*/
ClockDomain &parent;
/**
* Local clock divider of the domain
*/
const uint64_t clockDivider;
};
#endif
|
