1/***************************************************************************** 2 3 Licensed to Accellera Systems Initiative Inc. (Accellera) under one or 4 more contributor license agreements. See the NOTICE file distributed 5 with this work for additional information regarding copyright ownership. 6 Accellera licenses this file to you under the Apache License, Version 2.0 7 (the "License"); you may not use this file except in compliance with the 8 License. You may obtain a copy of the License at 9 10 http://www.apache.org/licenses/LICENSE-2.0 11 12 Unless required by applicable law or agreed to in writing, software 13 distributed under the License is distributed on an "AS IS" BASIS, 14 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 15 implied. See the License for the specific language governing 16 permissions and limitations under the License. 17 18 *****************************************************************************/ 19 20#ifndef __TLM_GLOBAL_QUANTUM_H__ 21#define __TLM_GLOBAL_QUANTUM_H__ 22 23#include <systemc> 24 25namespace tlm { 26 27// 28// tlm_global_quantum class 29// 30// The global quantum is the maximum time an initiator can run ahead of 31// systemC time. All initiators should synchronize on timingpoints that 32// are multiples of the global quantum value. 33// 34// sc_set_time_resolution can only be called before the first 35// sc_time object is created. This means that after setting the 36// global quantum it will not be possible to call sc_set_time_resolution. 37// If sc_set_time_resolution must be called this must be done before 38// the global quantum is set. 39// 40 41class tlm_global_quantum 42{ 43public: 44 // 45 // Returns a reference to the tlm_global_quantum singleton 46 // 47 static tlm_global_quantum& instance() 48 { 49 static tlm_global_quantum instance_; 50 return instance_; 51 } 52 53public: 54 55 // 56 // Setter/getter for the global quantum 57 // 58 void set(const sc_core::sc_time& t) 59 { 60 m_global_quantum = t; 61 } 62 63 const sc_core::sc_time& get() const 64 { 65 return m_global_quantum; 66 } 67 68 // 69 // This function will calculate the maximum value for the next local 70 // quantum for an initiator. All initiators should synchronize on 71 // integer multiples of the global quantum value. The value for the 72 // local quantum of an initiator can be smaller, but should never be 73 // greater than the value returned by this method. 74 // 75 sc_core::sc_time compute_local_quantum() 76 { 77 if (m_global_quantum != sc_core::SC_ZERO_TIME) { 78 const sc_core::sc_time current = sc_core::sc_time_stamp(); 79 const sc_core::sc_time g_quant = m_global_quantum; 80 return g_quant - (current % g_quant); 81 } else { 82 return sc_core::SC_ZERO_TIME; 83 } 84 } 85 86protected: 87 tlm_global_quantum() : m_global_quantum(sc_core::SC_ZERO_TIME) 88 { 89 } 90 91protected: 92 sc_core::sc_time m_global_quantum; 93}; 94 95} // namespace tlm 96 97#endif 98