clock_domain.hh revision 9793:6e6cefc1db1f
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; 59 60/** 61 * The ClockDomain provides clock to group of clocked objects bundled 62 * under the same clock domain. The clock domains provide support for 63 * a hierarchial structure with source and derived domains. 64 */ 65class ClockDomain : public SimObject 66{ 67 68 protected: 69 70 /** 71 * Pre-computed clock period in ticks. This is populated by the 72 * inheriting classes based on how their period is determined. 73 */ 74 Tick _clockPeriod; 75 76 /** 77 * Pointers to potential derived clock domains so we can propagate 78 * changes. 79 */ 80 std::vector<DerivedClockDomain*> children; 81 82 public: 83 84 typedef ClockDomainParams Params; 85 ClockDomain(const Params *p) : SimObject(p), _clockPeriod(0) {} 86 87 /** 88 * Get the clock period. 89 * 90 * @return Clock period in ticks 91 */ 92 inline Tick clockPeriod() const { return _clockPeriod; } 93 94 /** 95 * Add a derived domain. 96 * 97 * @param Derived domain to add as a child 98 */ 99 void addDerivedDomain(DerivedClockDomain *clock_domain) 100 { children.push_back(clock_domain); } 101 102}; 103 104/** 105 * The source clock domains provides the notion of a clock domain that is 106 * connected to a tunable clock source. It maintains the clock period and 107 * provides methods for setting/getting the clock. 108 */ 109class SrcClockDomain : public ClockDomain 110{ 111 112 public: 113 114 typedef SrcClockDomainParams Params; 115 SrcClockDomain(const Params *p); 116 117 /** 118 * Set new clock value 119 * @param clock The new clock period in ticks 120 */ 121 void clockPeriod(Tick clock_period); 122 123}; 124 125/** 126 * The derived clock domains provides the notion of a clock domain 127 * that is connected to a parent clock domain that can either be a 128 * source clock domain or a derived clock domain. It maintains the 129 * clock divider and provides methods for getting the clock. 130 */ 131class DerivedClockDomain: public ClockDomain 132{ 133 134 public: 135 136 typedef DerivedClockDomainParams Params; 137 DerivedClockDomain(const Params *p); 138 139 /** 140 * Called by the parent clock domain to propagate changes. This 141 * also involves propagating the change further to any children of 142 * the derived domain itself. 143 */ 144 void updateClockPeriod(); 145 146 private: 147 148 /** 149 * Reference to the parent clock domain this clock domain derives 150 * its clock period from 151 */ 152 ClockDomain &parent; 153 154 /** 155 * Local clock divider of the domain 156 */ 157 const uint64_t clockDivider; 158}; 159 160#endif 161