clock_domain.hh revision 9827
1/* 2 * Copyright (c) 2013 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions are 16 * met: redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer; 18 * redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution; 21 * neither the name of the copyright holders nor the names of its 22 * contributors may be used to endorse or promote products derived from 23 * this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * Authors: Vasileios Spiliopoulos 38 * Akash Bagdia 39 */ 40 41/** 42 * @file 43 * ClockDomain declarations. 44 */ 45 46#ifndef __SIM_CLOCK_DOMAIN_HH__ 47#define __SIM_CLOCK_DOMAIN_HH__ 48 49#include "base/statistics.hh" 50#include "params/ClockDomain.hh" 51#include "params/DerivedClockDomain.hh" 52#include "params/SrcClockDomain.hh" 53#include "sim/sim_object.hh" 54 55/** 56 * Forward declaration 57 */ 58class DerivedClockDomain; 59class VoltageDomain; 60 61/** 62 * The ClockDomain provides clock to group of clocked objects bundled 63 * under the same clock domain. The clock domains, in turn, are 64 * grouped into voltage domains. The clock domains provide support for 65 * a hierarchial structure with source and derived domains. 66 */ 67class ClockDomain : public SimObject 68{ 69 70 protected: 71 72 /** 73 * Pre-computed clock period in ticks. This is populated by the 74 * inheriting classes based on how their period is determined. 75 */ 76 Tick _clockPeriod; 77 78 /** 79 * Voltage domain this clock domain belongs to 80 */ 81 VoltageDomain *_voltageDomain; 82 83 /** 84 * Pointers to potential derived clock domains so we can propagate 85 * changes. 86 */ 87 std::vector<DerivedClockDomain*> children; 88 89 public: 90 91 typedef ClockDomainParams Params; 92 ClockDomain(const Params *p, VoltageDomain *voltage_domain) : 93 SimObject(p), 94 _clockPeriod(0), 95 _voltageDomain(voltage_domain) {} 96 97 /** 98 * Get the clock period. 99 * 100 * @return Clock period in ticks 101 */ 102 inline Tick clockPeriod() const { return _clockPeriod; } 103 104 /** 105 * Get the voltage domain. 106 * 107 * @return Voltage domain this clock domain belongs to 108 */ 109 inline VoltageDomain *voltageDomain() const { return _voltageDomain; } 110 111 112 /** 113 * Get the current voltage this clock domain operates at. 114 * 115 * @return Voltage applied to the clock domain 116 */ 117 inline double voltage() const; 118 119 /** 120 * Add a derived domain. 121 * 122 * @param Derived domain to add as a child 123 */ 124 void addDerivedDomain(DerivedClockDomain *clock_domain) 125 { children.push_back(clock_domain); } 126 127}; 128 129/** 130 * The source clock domains provides the notion of a clock domain that is 131 * connected to a tunable clock source. It maintains the clock period and 132 * provides methods for setting/getting the clock. 133 */ 134class SrcClockDomain : public ClockDomain 135{ 136 137 public: 138 139 typedef SrcClockDomainParams Params; 140 SrcClockDomain(const Params *p); 141 142 /** 143 * Set new clock value 144 * @param clock The new clock period in ticks 145 */ 146 void clockPeriod(Tick clock_period); 147 148}; 149 150/** 151 * The derived clock domains provides the notion of a clock domain 152 * that is connected to a parent clock domain that can either be a 153 * source clock domain or a derived clock domain. It maintains the 154 * clock divider and provides methods for getting the clock. 155 */ 156class DerivedClockDomain: public ClockDomain 157{ 158 159 public: 160 161 typedef DerivedClockDomainParams Params; 162 DerivedClockDomain(const Params *p); 163 164 /** 165 * Called by the parent clock domain to propagate changes. This 166 * also involves propagating the change further to any children of 167 * the derived domain itself. 168 */ 169 void updateClockPeriod(); 170 171 private: 172 173 /** 174 * Reference to the parent clock domain this clock domain derives 175 * its clock period from 176 */ 177 ClockDomain &parent; 178 179 /** 180 * Local clock divider of the domain 181 */ 182 const uint64_t clockDivider; 183}; 184 185#endif 186