From 5beab5bc17f9fa1f2340b491e073cfb973ad2e2b Mon Sep 17 00:00:00 2001 From: whitequark Date: Wed, 2 Dec 2020 08:25:27 +0000 Subject: cxxrtl: provide a way to perform unobtrusive power-on reset. Although it is always possible to destroy and recreate the design to simulate a power-on reset, this has two drawbacks: * Black boxes are also destroyed and recreated, which causes them to reacquire their resources, which might be costly and/or erase important state. * Pointers into the design are invalidated and have to be acquired again, which is costly and might be very inconvenient if they are captured elsewhere (especially through the C API). --- backends/cxxrtl/cxxrtl_backend.cc | 40 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) (limited to 'backends/cxxrtl/cxxrtl_backend.cc') diff --git a/backends/cxxrtl/cxxrtl_backend.cc b/backends/cxxrtl/cxxrtl_backend.cc index a48ea5b23..aab415720 100644 --- a/backends/cxxrtl/cxxrtl_backend.cc +++ b/backends/cxxrtl/cxxrtl_backend.cc @@ -1869,6 +1869,46 @@ struct CxxrtlWorker { } if (has_cells) f << "\n"; + f << indent << mangle(module) << "() {}\n"; + if (has_cells) { + f << indent << mangle(module) << "(adopt, " << mangle(module) << " other) :\n"; + bool first = true; + for (auto cell : module->cells()) { + if (is_internal_cell(cell->type)) + continue; + if (first) { + first = false; + } else { + f << ",\n"; + } + RTLIL::Module *cell_module = module->design->module(cell->type); + if (cell_module->get_bool_attribute(ID(cxxrtl_blackbox))) { + f << indent << " " << mangle(cell) << "(std::move(other." << mangle(cell) << "))"; + } else { + f << indent << " " << mangle(cell) << "(adopt {}, std::move(other." << mangle(cell) << "))"; + } + } + f << " {\n"; + inc_indent(); + for (auto cell : module->cells()) { + if (is_internal_cell(cell->type)) + continue; + RTLIL::Module *cell_module = module->design->module(cell->type); + if (cell_module->get_bool_attribute(ID(cxxrtl_blackbox))) + f << indent << mangle(cell) << "->reset();\n"; + } + dec_indent(); + f << indent << "}\n"; + } else { + f << indent << mangle(module) << "(adopt, " << mangle(module) << " other) {}\n"; + } + f << "\n"; + f << indent << "void reset() override {\n"; + inc_indent(); + f << indent << "*this = " << mangle(module) << "(adopt {}, std::move(*this));\n"; + dec_indent(); + f << indent << "}\n"; + f << "\n"; f << indent << "bool eval() override;\n"; f << indent << "bool commit() override;\n"; if (debug_info) -- cgit v1.2.3