sc_signal_rv.hh revision 13214
1/* 2 * Copyright 2018 Google, Inc. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: redistributions of source code must retain the above copyright 7 * notice, this list of conditions and the following disclaimer; 8 * redistributions in binary form must reproduce the above copyright 9 * notice, this list of conditions and the following disclaimer in the 10 * documentation and/or other materials provided with the distribution; 11 * neither the name of the copyright holders nor the names of its 12 * contributors may be used to endorse or promote products derived from 13 * this software without specific prior written permission. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 * Authors: Gabe Black 28 */ 29 30#ifndef __SYSTEMC_EXT_CHANNEL_SC_SIGNAL_RV_HH__ 31#define __SYSTEMC_EXT_CHANNEL_SC_SIGNAL_RV_HH__ 32 33#include "../core/sc_module.hh" // for sc_gen_unique_name 34#include "../core/scheduler.hh" 35#include "../dt/bit/sc_logic.hh" 36#include "../dt/bit/sc_lv.hh" 37#include "sc_signal.hh" 38#include "warn_unimpl.hh" 39 40namespace sc_dt 41{ 42 43template <int W> 44class sc_lv; 45 46}; 47 48namespace sc_core 49{ 50 51class sc_port_base; 52 53template <int W> 54class sc_signal_rv : public sc_signal<sc_dt::sc_lv<W>, SC_MANY_WRITERS> 55{ 56 public: 57 sc_signal_rv() : sc_signal<sc_dt::sc_lv<W>, SC_MANY_WRITERS>( 58 sc_gen_unique_name("signal_rv")) 59 {} 60 sc_signal_rv(const char *name) : 61 sc_signal<sc_dt::sc_lv<W>, SC_MANY_WRITERS>(name) 62 {} 63 virtual ~sc_signal_rv() {} 64 65 virtual void 66 register_port(sc_port_base &, const char *) 67 { 68 sc_channel_warn_unimpl(__PRETTY_FUNCTION__); 69 } 70 71 virtual void 72 write(const sc_dt::sc_lv<W> &l) 73 { 74 ::sc_gem5::Process *p = ::sc_gem5::scheduler.current(); 75 76 auto it = inputs.find(p); 77 if (it == inputs.end()) { 78 inputs.emplace(p, l); 79 this->request_update(); 80 } else if (it->second != l) { 81 it->second = l; 82 this->request_update(); 83 } 84 } 85 sc_signal_rv<W> & 86 operator = (const sc_dt::sc_lv<W> &l) 87 { 88 write(l); 89 return *this; 90 } 91 sc_signal_rv<W> & 92 operator = (const sc_signal_rv<W> &r) 93 { 94 write(r.read()); 95 return *this; 96 } 97 98 virtual const char *kind() const { return "sc_signal_rv"; } 99 100 protected: 101 virtual void 102 update() 103 { 104 using sc_dt::Log_0; 105 using sc_dt::Log_1; 106 using sc_dt::Log_Z; 107 using sc_dt::Log_X; 108 static sc_dt::sc_logic_value_t merge_table[4][4] = { 109 { Log_0, Log_X, Log_0, Log_X }, 110 { Log_X, Log_1, Log_1, Log_X }, 111 { Log_0, Log_1, Log_Z, Log_X }, 112 { Log_X, Log_X, Log_X, Log_X } 113 }; 114 115 // Resolve the inputs, and give the result to the underlying 116 // signal class. 117 for (int i = 0; i < W; i++) { 118 sc_dt::sc_logic_value_t bit = Log_Z; 119 for (auto &input: inputs) 120 bit = merge_table[bit][input.second.get_bit(i)]; 121 this->m_new_val.set_bit(i, bit); 122 } 123 124 // Ask the signal to update it's value. 125 sc_signal<sc_dt::sc_lv<W>, SC_MANY_WRITERS>::update(); 126 } 127 128 private: 129 // Disabled 130 sc_signal_rv(const sc_signal_rv<W> &) : 131 sc_signal<sc_dt::sc_lv<W>, SC_MANY_WRITERS>() 132 {} 133 134 std::map<::sc_gem5::Process *, sc_dt::sc_lv<W> > inputs; 135}; 136 137} // namespace sc_core 138 139#endif //__SYSTEMC_EXT_CHANNEL_SC_SIGNAL_RV_HH__ 140