clocked_object.hh revision 10236
12789Sktlim@umich.edu/* 28733Sgeoffrey.blake@arm.com * Copyright (c) 2012-2013 ARM Limited 38733Sgeoffrey.blake@arm.com * Copyright (c) 2013 Cornell University 48733Sgeoffrey.blake@arm.com * All rights reserved 58733Sgeoffrey.blake@arm.com * 68733Sgeoffrey.blake@arm.com * The license below extends only to copyright in the software and shall 78733Sgeoffrey.blake@arm.com * not be construed as granting a license to any other intellectual 88733Sgeoffrey.blake@arm.com * property including but not limited to intellectual property relating 98733Sgeoffrey.blake@arm.com * to a hardware implementation of the functionality of the software 108733Sgeoffrey.blake@arm.com * licensed hereunder. You may use the software subject to the license 118733Sgeoffrey.blake@arm.com * terms below provided that you ensure that this notice is replicated 128733Sgeoffrey.blake@arm.com * unmodified and in its entirety in all distributions of the software, 138733Sgeoffrey.blake@arm.com * modified or unmodified, in source code or in binary form. 142789Sktlim@umich.edu * 152789Sktlim@umich.edu * Redistribution and use in source and binary forms, with or without 162789Sktlim@umich.edu * modification, are permitted provided that the following conditions are 172789Sktlim@umich.edu * met: redistributions of source code must retain the above copyright 182789Sktlim@umich.edu * notice, this list of conditions and the following disclaimer; 192789Sktlim@umich.edu * redistributions in binary form must reproduce the above copyright 202789Sktlim@umich.edu * notice, this list of conditions and the following disclaimer in the 212789Sktlim@umich.edu * documentation and/or other materials provided with the distribution; 222789Sktlim@umich.edu * neither the name of the copyright holders nor the names of its 232789Sktlim@umich.edu * contributors may be used to endorse or promote products derived from 242789Sktlim@umich.edu * this software without specific prior written permission. 252789Sktlim@umich.edu * 262789Sktlim@umich.edu * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 272789Sktlim@umich.edu * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 282789Sktlim@umich.edu * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 292789Sktlim@umich.edu * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 302789Sktlim@umich.edu * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 312789Sktlim@umich.edu * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 322789Sktlim@umich.edu * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 332789Sktlim@umich.edu * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 342789Sktlim@umich.edu * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 352789Sktlim@umich.edu * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 362789Sktlim@umich.edu * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 372789Sktlim@umich.edu * 382789Sktlim@umich.edu * Authors: Andreas Hansson 392789Sktlim@umich.edu * Christopher Torng 402789Sktlim@umich.edu */ 418733Sgeoffrey.blake@arm.com 422789Sktlim@umich.edu/** 432789Sktlim@umich.edu * @file 442789Sktlim@umich.edu * ClockedObject declaration and implementation. 452789Sktlim@umich.edu */ 462789Sktlim@umich.edu 478229Snate@binkert.org#ifndef __SIM_CLOCKED_OBJECT_HH__ 482789Sktlim@umich.edu#define __SIM_CLOCKED_OBJECT_HH__ 492789Sktlim@umich.edu 503348Sbinkertn@umich.edu#include "base/intmath.hh" 512789Sktlim@umich.edu#include "base/misc.hh" 528733Sgeoffrey.blake@arm.com#include "params/ClockedObject.hh" 538733Sgeoffrey.blake@arm.com#include "sim/core.hh" 542789Sktlim@umich.edu#include "sim/clock_domain.hh" 552789Sktlim@umich.edu#include "sim/sim_object.hh" 563565Sgblack@eecs.umich.edu 572789Sktlim@umich.edu/** 582789Sktlim@umich.edu * The ClockedObject class extends the SimObject with a clock and 592789Sktlim@umich.edu * accessor functions to relate ticks to the cycles of the object. 602789Sktlim@umich.edu */ 618733Sgeoffrey.blake@arm.comclass ClockedObject : public SimObject 622789Sktlim@umich.edu{ 632789Sktlim@umich.edu 642789Sktlim@umich.edu private: 652789Sktlim@umich.edu 662789Sktlim@umich.edu // the tick value of the next clock edge (>= curTick()) at the 672789Sktlim@umich.edu // time of the last call to update() 682789Sktlim@umich.edu mutable Tick tick; 692789Sktlim@umich.edu 702789Sktlim@umich.edu // The cycle counter value corresponding to the current value of 712789Sktlim@umich.edu // 'tick' 728733Sgeoffrey.blake@arm.com mutable Cycles cycle; 738733Sgeoffrey.blake@arm.com 742789Sktlim@umich.edu /** 752789Sktlim@umich.edu * Prevent inadvertent use of the copy constructor and assignment 762789Sktlim@umich.edu * operator by making them private. 772789Sktlim@umich.edu */ 782789Sktlim@umich.edu ClockedObject(ClockedObject&); 792789Sktlim@umich.edu ClockedObject& operator=(ClockedObject&); 802789Sktlim@umich.edu 812789Sktlim@umich.edu /** 822789Sktlim@umich.edu * Align cycle and tick to the next clock edge if not already done. When 832789Sktlim@umich.edu * complete, tick must be at least curTick(). 842789Sktlim@umich.edu */ 852789Sktlim@umich.edu void update() const 862789Sktlim@umich.edu { 878733Sgeoffrey.blake@arm.com // both tick and cycle are up-to-date and we are done, note 882789Sktlim@umich.edu // that the >= is important as it captures cases where tick 892789Sktlim@umich.edu // has already passed curTick() 908733Sgeoffrey.blake@arm.com if (tick >= curTick()) 918733Sgeoffrey.blake@arm.com return; 928733Sgeoffrey.blake@arm.com 933402Sktlim@umich.edu // optimise for the common case and see if the tick should be 943402Sktlim@umich.edu // advanced by a single clock period 953402Sktlim@umich.edu tick += clockPeriod(); 962789Sktlim@umich.edu ++cycle; 972789Sktlim@umich.edu 988733Sgeoffrey.blake@arm.com // see if we are done at this point 992789Sktlim@umich.edu if (tick >= curTick()) 1002789Sktlim@umich.edu return; 1012789Sktlim@umich.edu 1022789Sktlim@umich.edu // if not, we have to recalculate the cycle and tick, we 1032789Sktlim@umich.edu // perform the calculations in terms of relative cycles to 1042789Sktlim@umich.edu // allow changes to the clock period in the future 1052789Sktlim@umich.edu Cycles elapsedCycles(divCeil(curTick() - tick, clockPeriod())); 1062789Sktlim@umich.edu cycle += elapsedCycles; 1072789Sktlim@umich.edu tick += elapsedCycles * clockPeriod(); 1082789Sktlim@umich.edu } 1092789Sktlim@umich.edu 1102789Sktlim@umich.edu /** 1112789Sktlim@umich.edu * The clock domain this clocked object belongs to 1122789Sktlim@umich.edu */ 1132789Sktlim@umich.edu ClockDomain &clockDomain; 1142789Sktlim@umich.edu 1152789Sktlim@umich.edu protected: 1162789Sktlim@umich.edu 1172789Sktlim@umich.edu /** 1182789Sktlim@umich.edu * Create a clocked object and set the clock domain based on the 1192789Sktlim@umich.edu * parameters. 1202789Sktlim@umich.edu */ 1212789Sktlim@umich.edu ClockedObject(const ClockedObjectParams* p) : 1222789Sktlim@umich.edu SimObject(p), tick(0), cycle(0), clockDomain(*p->clk_domain) 1232789Sktlim@umich.edu { 1242789Sktlim@umich.edu // Register with the clock domain, so that if the clock domain 1252789Sktlim@umich.edu // frequency changes, we can update this object's tick. 1262789Sktlim@umich.edu clockDomain.registerWithClockDomain(this); 1272789Sktlim@umich.edu } 1282789Sktlim@umich.edu 1292789Sktlim@umich.edu /** 1302789Sktlim@umich.edu * Virtual destructor due to inheritance. 1312789Sktlim@umich.edu */ 1322789Sktlim@umich.edu virtual ~ClockedObject() { } 1332789Sktlim@umich.edu 1342789Sktlim@umich.edu /** 1352789Sktlim@umich.edu * Reset the object's clock using the current global tick value. Likely 1362789Sktlim@umich.edu * to be used only when the global clock is reset. Currently, this done 1372789Sktlim@umich.edu * only when Ruby is done warming up the memory system. 1382789Sktlim@umich.edu */ 1392789Sktlim@umich.edu void resetClock() const 1402789Sktlim@umich.edu { 1412789Sktlim@umich.edu Cycles elapsedCycles(divCeil(curTick(), clockPeriod())); 1422789Sktlim@umich.edu cycle = elapsedCycles; 1438733Sgeoffrey.blake@arm.com tick = elapsedCycles * clockPeriod(); 1442789Sktlim@umich.edu } 1458733Sgeoffrey.blake@arm.com 1468733Sgeoffrey.blake@arm.com public: 1478733Sgeoffrey.blake@arm.com 1488733Sgeoffrey.blake@arm.com /** 1498733Sgeoffrey.blake@arm.com * Update the tick to the current tick. 1508733Sgeoffrey.blake@arm.com * 1518733Sgeoffrey.blake@arm.com */ 1522789Sktlim@umich.edu inline void updateClockPeriod() const 1532789Sktlim@umich.edu { 1548733Sgeoffrey.blake@arm.com update(); 1558733Sgeoffrey.blake@arm.com } 1562789Sktlim@umich.edu 1578733Sgeoffrey.blake@arm.com /** 1588733Sgeoffrey.blake@arm.com * Determine the tick when a cycle begins, by default the current one, but 1598733Sgeoffrey.blake@arm.com * the argument also enables the caller to determine a future cycle. When 1608733Sgeoffrey.blake@arm.com * curTick() is on a clock edge, the number of cycles in the parameter is 1612789Sktlim@umich.edu * added to curTick() to be returned. When curTick() is not aligned to a 1628733Sgeoffrey.blake@arm.com * clock edge, the number of cycles in the parameter is added to the next 1638733Sgeoffrey.blake@arm.com * clock edge. 1642789Sktlim@umich.edu * 1658733Sgeoffrey.blake@arm.com * @param cycles The number of cycles into the future 1668733Sgeoffrey.blake@arm.com * 1678733Sgeoffrey.blake@arm.com * @return The start tick when the requested clock edge occurs. Precisely, 1688733Sgeoffrey.blake@arm.com * this tick can be 1698733Sgeoffrey.blake@arm.com * curTick() + [0, clockPeriod()) + clockPeriod() * cycles 1708733Sgeoffrey.blake@arm.com */ 1718733Sgeoffrey.blake@arm.com inline Tick clockEdge(Cycles cycles = Cycles(0)) const 1728733Sgeoffrey.blake@arm.com { 1738733Sgeoffrey.blake@arm.com // align tick to the next clock edge 1748733Sgeoffrey.blake@arm.com update(); 1758733Sgeoffrey.blake@arm.com 1768733Sgeoffrey.blake@arm.com // figure out when this future cycle is 1778733Sgeoffrey.blake@arm.com return tick + clockPeriod() * cycles; 1788733Sgeoffrey.blake@arm.com } 1798733Sgeoffrey.blake@arm.com 1808733Sgeoffrey.blake@arm.com /** 1818733Sgeoffrey.blake@arm.com * Determine the current cycle, corresponding to a tick aligned to 1828733Sgeoffrey.blake@arm.com * a clock edge. 1838733Sgeoffrey.blake@arm.com * 1848733Sgeoffrey.blake@arm.com * @return When curTick() is on a clock edge, return the Cycle corresponding 1858733Sgeoffrey.blake@arm.com * to that clock edge. When curTick() is not on a clock edge, return the 1868733Sgeoffrey.blake@arm.com * Cycle corresponding to the next clock edge. 1878733Sgeoffrey.blake@arm.com */ 1888733Sgeoffrey.blake@arm.com inline Cycles curCycle() const 1898733Sgeoffrey.blake@arm.com { 1908733Sgeoffrey.blake@arm.com // align cycle to the next clock edge. 1918733Sgeoffrey.blake@arm.com update(); 1928733Sgeoffrey.blake@arm.com 1938733Sgeoffrey.blake@arm.com return cycle; 1948733Sgeoffrey.blake@arm.com } 1958733Sgeoffrey.blake@arm.com 1968733Sgeoffrey.blake@arm.com /** 1978733Sgeoffrey.blake@arm.com * Based on the clock of the object, determine the start tick of the first 1988733Sgeoffrey.blake@arm.com * cycle that is at least one cycle in the future. When curTick() is at the 1998733Sgeoffrey.blake@arm.com * current cycle edge, this returns the next clock edge. When calling this 2008733Sgeoffrey.blake@arm.com * during the middle of a cycle, this returns 2 clock edges in the future. 2018733Sgeoffrey.blake@arm.com * 2028733Sgeoffrey.blake@arm.com * @return The start tick of the first cycle that is at least one cycle in 2038733Sgeoffrey.blake@arm.com * the future. Precisely, the returned tick can be in the range 2048733Sgeoffrey.blake@arm.com * curTick() + [clockPeriod(), 2 * clockPeriod()) 2058733Sgeoffrey.blake@arm.com */ 2068733Sgeoffrey.blake@arm.com Tick nextCycle() const 2078733Sgeoffrey.blake@arm.com { return clockEdge(Cycles(1)); } 2088733Sgeoffrey.blake@arm.com 2098733Sgeoffrey.blake@arm.com inline uint64_t frequency() const 2108733Sgeoffrey.blake@arm.com { 2118733Sgeoffrey.blake@arm.com return SimClock::Frequency / clockPeriod(); 2128733Sgeoffrey.blake@arm.com } 2138733Sgeoffrey.blake@arm.com 2148733Sgeoffrey.blake@arm.com inline Tick clockPeriod() const 2158733Sgeoffrey.blake@arm.com { 2168733Sgeoffrey.blake@arm.com return clockDomain.clockPeriod(); 2178733Sgeoffrey.blake@arm.com } 2188733Sgeoffrey.blake@arm.com 2192789Sktlim@umich.edu inline Cycles ticksToCycles(Tick t) const 2202789Sktlim@umich.edu { return Cycles(divCeil(t, clockPeriod())); } 2218733Sgeoffrey.blake@arm.com 2228733Sgeoffrey.blake@arm.com}; 2238733Sgeoffrey.blake@arm.com 2248733Sgeoffrey.blake@arm.com#endif //__SIM_CLOCKED_OBJECT_HH__ 2258733Sgeoffrey.blake@arm.com