blob: a68736f1ff7d1c62d7728bb5cb370eee685cdacf [file] [log] [blame]
/*
* Copyright 2018 Google, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Gabe Black
*/
#include "systemc/core/process.hh"
#include "systemc/core/scheduler.hh"
#include "systemc/ext/channel/sc_signal_resolved.hh"
#include "systemc/ext/core/sc_module.hh" // for sc_gen_unique_name
namespace sc_core
{
sc_signal_resolved::sc_signal_resolved() : sc_interface(),
sc_signal<sc_dt::sc_logic, SC_MANY_WRITERS>(
sc_gen_unique_name("signal_resolved"))
{}
sc_signal_resolved::sc_signal_resolved(const char *name) :
sc_interface(), sc_signal<sc_dt::sc_logic, SC_MANY_WRITERS>(name)
{}
sc_signal_resolved::~sc_signal_resolved() {}
void sc_signal_resolved::register_port(sc_port_base &, const char *) {}
void
sc_signal_resolved::write(const sc_dt::sc_logic &l)
{
::sc_gem5::Process *p = ::sc_gem5::scheduler.current();
auto it = inputs.find(p);
if (it == inputs.end()) {
inputs.emplace(p, l);
request_update();
} else if (it->second != l) {
it->second = l;
request_update();
}
}
sc_signal_resolved &
sc_signal_resolved::operator = (const sc_dt::sc_logic &l)
{
write(l);
return *this;
}
sc_signal_resolved &
sc_signal_resolved::operator = (const sc_signal_resolved &r)
{
write(r.read());
return *this;
}
void
sc_signal_resolved::update()
{
using sc_dt::Log_0;
using sc_dt::Log_1;
using sc_dt::Log_Z;
using sc_dt::Log_X;
static sc_dt::sc_logic_value_t merge_table[4][4] = {
{ Log_0, Log_X, Log_0, Log_X },
{ Log_X, Log_1, Log_1, Log_X },
{ Log_0, Log_1, Log_Z, Log_X },
{ Log_X, Log_X, Log_X, Log_X }
};
// Resolve the inputs, and give the result to the underlying signal class.
m_new_val = Log_Z;
for (auto &input: inputs)
m_new_val = merge_table[m_new_val.value()][input.second.value()];
// Ask the signal to update it's value.
sc_signal<sc_dt::sc_logic, SC_MANY_WRITERS>::update();
}
} // namespace sc_core