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/*
* 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
{
private:
/**
* Stat to report clock period of clock domain
*/
Stats::Value currentClock;
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) {}
void regStats();
/**
* 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
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