/* * yosys -- Yosys Open SYnthesis Suite * * Copyright (C) 2012 Claire Xenia Wolf * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * */ #include "kernel/yosys.h" #include "kernel/sigtools.h" #include "kernel/celltypes.h" #include "kernel/mem.h" #include USING_YOSYS_NAMESPACE PRIVATE_NAMESPACE_BEGIN struct SimShared { bool debug = false; bool hide_internal = true; bool writeback = false; bool zinit = false; int rstlen = 1; }; void zinit(State &v) { if (v != State::S1) v = State::S0; } void zinit(Const &v) { for (auto &bit : v.bits) zinit(bit); } struct SimInstance { SimShared *shared; Module *module; Cell *instance; SimInstance *parent; dict children; SigMap sigmap; dict state_nets; dict> upd_cells; dict> upd_outports; pool dirty_bits; pool dirty_cells; pool dirty_memories; pool dirty_children; struct ff_state_t { State past_clock; Const past_d; }; struct mem_state_t { Mem *mem; std::vector past_wr_clk; std::vector past_wr_en; std::vector past_wr_addr; std::vector past_wr_data; Const data; }; dict ff_database; dict mem_database; pool formal_database; dict mem_cells; std::vector memories; dict> vcd_database; SimInstance(SimShared *shared, Module *module, Cell *instance = nullptr, SimInstance *parent = nullptr) : shared(shared), module(module), instance(instance), parent(parent), sigmap(module) { log_assert(module); if (parent) { log_assert(parent->children.count(instance) == 0); parent->children[instance] = this; } for (auto wire : module->wires()) { SigSpec sig = sigmap(wire); for (int i = 0; i < GetSize(sig); i++) { if (state_nets.count(sig[i]) == 0) state_nets[sig[i]] = State::Sx; if (wire->port_output) { upd_outports[sig[i]].insert(wire); dirty_bits.insert(sig[i]); } } if (wire->attributes.count(ID::init)) { Const initval = wire->attributes.at(ID::init); for (int i = 0; i < GetSize(sig) && i < GetSize(initval); i++) if (initval[i] == State::S0 || initval[i] == State::S1) { state_nets[sig[i]] = initval[i]; dirty_bits.insert(sig[i]); } } } memories = Mem::get_all_memories(module); for (auto &mem : memories) { auto &mdb = mem_database[mem.memid]; mdb.mem = &mem; for (auto &port : mem.wr_ports) { mdb.past_wr_clk.push_back(Const(State::Sx)); mdb.past_wr_en.push_back(Const(State::Sx, GetSize(port.en))); mdb.past_wr_addr.push_back(Const(State::Sx, GetSize(port.addr))); mdb.past_wr_data.push_back(Const(State::Sx, GetSize(port.data))); } mdb.data = mem.get_init_data(); } for (auto cell : module->cells()) { Module *mod = module->design->module(cell->type); if (mod != nullptr) { dirty_children.insert(new SimInstance(shared, mod, cell, this)); } for (auto &port : cell->connections()) { if (cell->input(port.first)) for (auto bit : sigmap(port.second)) { upd_cells[bit].insert(cell); // Make sure cell inputs connected to constants are updated in the first cycle if (bit.wire == nullptr) dirty_bits.insert(bit); } } if (cell->type.in(ID($dff))) { ff_state_t ff; ff.past_clock = State::Sx; ff.past_d = Const(State::Sx, cell->getParam(ID::WIDTH).as_int()); ff_database[cell] = ff; } if (cell->is_mem_cell()) { mem_cells[cell] = cell->parameters.at(ID::MEMID).decode_string(); } if (cell->type.in(ID($assert), ID($cover), ID($assume))) { formal_database.insert(cell); } } if (shared->zinit) { for (auto &it : ff_database) { Cell *cell = it.first; ff_state_t &ff = it.second; zinit(ff.past_d); SigSpec qsig = cell->getPort(ID::Q); Const qdata = get_state(qsig); zinit(qdata); set_state(qsig, qdata); } for (auto &it : mem_database) { mem_state_t &mem = it.second; for (auto &val : mem.past_wr_en) zinit(val); zinit(mem.data); } } } ~SimInstance() { for (auto child : children) delete child.second; } IdString name() const { if (instance != nullptr) return instance->name; return module->name; } std::string hiername() const { if (instance != nullptr) return parent->hiername() + "." + log_id(instance->name); return log_id(module->name); } Const get_state(SigSpec sig) { Const value; for (auto bit : sigmap(sig)) if (bit.wire == nullptr) value.bits.push_back(bit.data); else if (state_nets.count(bit)) value.bits.push_back(state_nets.at(bit)); else value.bits.push_back(State::Sz); if (shared->debug) log("[%s] get %s: %s\n", hiername().c_str(), log_signal(sig), log_signal(value)); return value; } bool set_state(SigSpec sig, Const value) { bool did_something = false; sig = sigmap(sig); log_assert(GetSize(sig) <= GetSize(value)); for (int i = 0; i < GetSize(sig); i++) if (state_nets.at(sig[i]) != value[i]) { state_nets.at(sig[i]) = value[i]; dirty_bits.insert(sig[i]); did_something = true; } if (shared->debug) log("[%s] set %s: %s\n", hiername().c_str(), log_signal(sig), log_signal(value)); return did_something; } void update_cell(Cell *cell) { if (ff_database.count(cell)) return; if (formal_database.count(cell)) return; if (mem_cells.count(cell)) { dirty_memories.insert(mem_cells[cell]); return; } if (children.count(cell)) { auto child = children.at(cell); for (auto &conn: cell->connections()) if (cell->input(conn.first) && GetSize(conn.second)) { Const value = get_state(conn.second); child->set_state(child->module->wire(conn.first), value); } dirty_children.insert(child); return; } if (yosys_celltypes.cell_evaluable(cell->type)) { RTLIL::SigSpec sig_a, sig_b, sig_c, sig_d, sig_s, sig_y; bool has_a, has_b, has_c, has_d, has_s, has_y; has_a = cell->hasPort(ID::A); has_b = cell->hasPort(ID::B); has_c = cell->hasPort(ID::C); has_d = cell->hasPort(ID::D); has_s = cell->hasPort(ID::S); has_y = cell->hasPort(ID::Y); if (has_a) sig_a = cell->getPort(ID::A); if (has_b) sig_b = cell->getPort(ID::B); if (has_c) sig_c = cell->getPort(ID::C); if (has_d) sig_d = cell->getPort(ID::D); if (has_s) sig_s = cell->getPort(ID::S); if (has_y) sig_y = cell->getPort(ID::Y); if (shared->debug) log("[%s] eval %s (%s)\n", hiername().c_str(), log_id(cell), log_id(cell->type)); // Simple (A -> Y) and (A,B -> Y) cells if (has_a && !has_c && !has_d && !has_s && has_y) { set_state(sig_y, CellTypes::eval(cell, get_state(sig_a), get_state(sig_b))); return; } // (A,B,C -> Y) cells if (has_a && has_b && has_c && !has_d && !has_s && has_y) { set_state(sig_y, CellTypes::eval(cell, get_state(sig_a), get_state(sig_b), get_state(sig_c))); return; } // (A,B,S -> Y) cells if (has_a && has_b && !has_c && !has_d && has_s && has_y) { set_state(sig_y, CellTypes::eval(cell, get_state(sig_a), get_state(sig_b), get_state(sig_s))); return; } log_warning("Unsupported evaluable cell type: %s (%s.%s)\n", log_id(cell->type), log_id(module), log_id(cell)); return; } log_error("Unsupported cell type: %s (%s.%s)\n", log_id(cell->type), log_id(module), log_id(cell)); } void update_memory(IdString id) { auto &mdb = mem_database[id]; auto &mem = *mdb.mem; for (int port_idx = 0; port_idx < GetSize(mem.rd_ports); port_idx++) { auto &port = mem.rd_ports[port_idx]; Const addr = get_state(port.addr); Const data = Const(State::Sx, mem.width << port.wide_log2); if (port.clk_enable) log_error("Memory %s.%s has clocked read ports. Run 'memory' with -nordff.\n", log_id(module), log_id(mem.memid)); if (addr.is_fully_def()) { int index = addr.as_int() - mem.start_offset; if (index >= 0 && index < mem.size) data = mdb.data.extract(index*mem.width, mem.width << port.wide_log2); } set_state(port.data, data); } } void update_ph1() { pool queue_cells; pool queue_outports; queue_cells.swap(dirty_cells); while (1) { for (auto bit : dirty_bits) { if (upd_cells.count(bit)) for (auto cell : upd_cells.at(bit)) queue_cells.insert(cell); if (upd_outports.count(bit) && parent != nullptr) for (auto wire : upd_outports.at(bit)) queue_outports.insert(wire); } dirty_bits.clear(); if (!queue_cells.empty()) { for (auto cell : queue_cells) update_cell(cell); queue_cells.clear(); continue; } for (auto &memid : dirty_memories) update_memory(memid); dirty_memories.clear(); for (auto wire : queue_outports) if (instance->hasPort(wire->name)) { Const value = get_state(wire); parent->set_state(instance->getPort(wire->name), value); } queue_outports.clear(); for (auto child : dirty_children) child->update_ph1(); dirty_children.clear(); if (dirty_bits.empty()) break; } } bool update_ph2() { bool did_something = false; for (auto &it : ff_database) { Cell *cell = it.first; ff_state_t &ff = it.second; if (cell->type.in(ID($dff))) { bool clkpol = cell->getParam(ID::CLK_POLARITY).as_bool(); State current_clock = get_state(cell->getPort(ID::CLK))[0]; if (clkpol ? (ff.past_clock == State::S1 || current_clock != State::S1) : (ff.past_clock == State::S0 || current_clock != State::S0)) continue; if (set_state(cell->getPort(ID::Q), ff.past_d)) did_something = true; } } for (auto &it : mem_database) { mem_state_t &mdb = it.second; auto &mem = *mdb.mem; for (int port_idx = 0; port_idx < GetSize(mem.wr_ports); port_idx++) { auto &port = mem.wr_ports[port_idx]; Const addr, data, enable; if (!port.clk_enable) { addr = get_state(port.addr); data = get_state(port.data); enable = get_state(port.en); } else { if (port.clk_polarity ? (mdb.past_wr_clk[port_idx] == State::S1 || get_state(port.clk) != State::S1) : (mdb.past_wr_clk[port_idx] == State::S0 || get_state(port.clk) != State::S0)) continue; addr = mdb.past_wr_addr[port_idx]; data = mdb.past_wr_data[port_idx]; enable = mdb.past_wr_en[port_idx]; } if (addr.is_fully_def()) { int index = addr.as_int() - mem.start_offset; if (index >= 0 && index < mem.size) for (int i = 0; i < (mem.width << port.wide_log2); i++) if (enable[i] == State::S1 && mdb.data.bits.at(index*mem.width+i) != data[i]) { mdb.data.bits.at(index*mem.width+i) = data[i]; dirty_memories.insert(mem.memid); did_something = true; } } } } for (auto it : children) if (it.second->update_ph2()) { dirty_children.insert(it.second); did_something = true; } return did_something; } void update_ph3() { for (auto &it : ff_database) { Cell *cell = it.first; ff_state_t &ff = it.second; if (cell->type.in(ID($dff))) { ff.past_clock = get_state(cell->getPort(ID::CLK))[0]; ff.past_d = get_state(cell->getPort(ID::D)); } } for (auto &it : mem_database) { mem_state_t &mem = it.second; for (int i = 0; i < GetSize(mem.mem->wr_ports); i++) { auto &port = mem.mem->wr_ports[i]; mem.past_wr_clk[i] = get_state(port.clk); mem.past_wr_en[i] = get_state(port.en); mem.past_wr_addr[i] = get_state(port.addr); mem.past_wr_data[i] = get_state(port.data); } } for (auto cell : formal_database) { string label = log_id(cell); if (cell->attributes.count(ID::src)) label = cell->attributes.at(ID::src).decode_string(); State a = get_state(cell->getPort(ID::A))[0]; State en = get_state(cell->getPort(ID::EN))[0]; if (cell->type == ID($cover) && en == State::S1 && a != State::S1) log("Cover %s.%s (%s) reached.\n", hiername().c_str(), log_id(cell), label.c_str()); if (cell->type == ID($assume) && en == State::S1 && a != State::S1) log("Assumption %s.%s (%s) failed.\n", hiername().c_str(), log_id(cell), label.c_str()); if (cell->type == ID($assert) && en == State::S1 && a != State::S1) log_warning("Assert %s.%s (%s) failed.\n", hiername().c_str(), log_id(cell), label.c_str()); } for (auto it : children) it.second->update_ph3(); } void writeback(pool &wbmods) { if (wbmods.count(module)) log_error("Instance %s of module %s is not unique: Writeback not possible. (Fix by running 'uniquify'.)\n", hiername().c_str(), log_id(module)); wbmods.insert(module); for (auto wire : module->wires()) wire->attributes.erase(ID::init); for (auto &it : ff_database) { Cell *cell = it.first; SigSpec sig_q = cell->getPort(ID::Q); Const initval = get_state(sig_q); for (int i = 0; i < GetSize(sig_q); i++) { Wire *w = sig_q[i].wire; if (w->attributes.count(ID::init) == 0) w->attributes[ID::init] = Const(State::Sx, GetSize(w)); w->attributes[ID::init][sig_q[i].offset] = initval[i]; } } for (auto &it : mem_database) { mem_state_t &mem = it.second; mem.mem->clear_inits(); MemInit minit; minit.addr = mem.mem->start_offset; minit.data = mem.data; minit.en = Const(State::S1, mem.mem->width); mem.mem->inits.push_back(minit); mem.mem->emit(); } for (auto it : children) it.second->writeback(wbmods); } void write_vcd_header(std::ofstream &f, int &id) { f << stringf("$scope module %s $end\n", log_id(name())); for (auto wire : module->wires()) { if (shared->hide_internal && wire->name[0] == '$') continue; f << stringf("$var wire %d n%d %s%s $end\n", GetSize(wire), id, wire->name[0] == '$' ? "\\" : "", log_id(wire)); vcd_database[wire] = make_pair(id++, Const()); } for (auto child : children) child.second->write_vcd_header(f, id); f << stringf("$upscope $end\n"); } void write_vcd_step(std::ofstream &f) { for (auto &it : vcd_database) { Wire *wire = it.first; Const value = get_state(wire); int id = it.second.first; if (it.second.second == value) continue; it.second.second = value; f << "b"; for (int i = GetSize(value)-1; i >= 0; i--) { switch (value[i]) { case State::S0: f << "0"; break; case State::S1: f << "1"; break; case State::Sx: f << "x"; break; default: f << "z"; } } f << stringf(" n%d\n", id); } for (auto child : children) child.second->write_vcd_step(f); } }; struct SimWorker : SimShared { SimInstance *top = nullptr; std::ofstream vcdfile; pool clock, clockn, reset, resetn; std::string timescale; ~SimWorker() { delete top; } void write_vcd_header() { if (!vcdfile.is_open()) return; vcdfile << stringf("$version %s $end\n", yosys_version_str); std::time_t t = std::time(nullptr); char mbstr[255]; if (std::strftime(mbstr, sizeof(mbstr), "%c", std::localtime(&t))) { vcdfile << stringf("$date ") << mbstr << stringf(" $end\n"); } if (!timescale.empty()) vcdfile << stringf("$timescale %s $end\n", timescale.c_str()); int id = 1; top->write_vcd_header(vcdfile, id); vcdfile << stringf("$enddefinitions $end\n"); } void write_vcd_step(int t) { if (!vcdfile.is_open()) return; vcdfile << stringf("#%d\n", t); top->write_vcd_step(vcdfile); } void update() { while (1) { if (debug) log("\n-- ph1 --\n"); top->update_ph1(); if (debug) log("\n-- ph2 --\n"); if (!top->update_ph2()) break; } if (debug) log("\n-- ph3 --\n"); top->update_ph3(); } void set_inports(pool ports, State value) { for (auto portname : ports) { Wire *w = top->module->wire(portname); if (w == nullptr) log_error("Can't find port %s on module %s.\n", log_id(portname), log_id(top->module)); top->set_state(w, value); } } void run(Module *topmod, int numcycles) { log_assert(top == nullptr); top = new SimInstance(this, topmod); if (debug) log("\n===== 0 =====\n"); else log("Simulating cycle 0.\n"); set_inports(reset, State::S1); set_inports(resetn, State::S0); set_inports(clock, State::Sx); set_inports(clockn, State::Sx); update(); write_vcd_header(); write_vcd_step(0); for (int cycle = 0; cycle < numcycles; cycle++) { if (debug) log("\n===== %d =====\n", 10*cycle + 5); set_inports(clock, State::S0); set_inports(clockn, State::S1); update(); write_vcd_step(10*cycle + 5); if (debug) log("\n===== %d =====\n", 10*cycle + 10); else log("Simulating cycle %d.\n", cycle+1); set_inports(clock, State::S1); set_inports(clockn, State::S0); if (cycle+1 == rstlen) { set_inports(reset, State::S0); set_inports(resetn, State::S1); } update(); write_vcd_step(10*cycle + 10); } write_vcd_step(10*numcycles + 2); if (writeback) { pool wbmods; top->writeback(wbmods); } } }; struct SimPass : public Pass { SimPass() : Pass("sim", "simulate the circuit") { } void help() override { // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| log("\n"); log(" sim [options] [top-level]\n"); log("\n"); log("This command simulates the circuit using the given top-level module.\n"); log("\n"); log(" -vcd \n"); log(" write the simulation results to the given VCD file\n"); log("\n"); log(" -clock \n"); log(" name of top-level clock input\n"); log("\n"); log(" -clockn \n"); log(" name of top-level clock input (inverse polarity)\n"); log("\n"); log(" -reset \n"); log(" name of top-level reset input (active high)\n"); log("\n"); log(" -resetn \n"); log(" name of top-level inverted reset input (active low)\n"); log("\n"); log(" -rstlen \n"); log(" number of cycles reset should stay active (default: 1)\n"); log("\n"); log(" -zinit\n"); log(" zero-initialize all uninitialized regs and memories\n"); log("\n"); log(" -timescale \n"); log(" include the specified timescale declaration in the vcd\n"); log("\n"); log(" -n \n"); log(" number of cycles to simulate (default: 20)\n"); log("\n"); log(" -a\n"); log(" include all nets in VCD output, not just those with public names\n"); log("\n"); log(" -w\n"); log(" writeback mode: use final simulation state as new init state\n"); log("\n"); log(" -d\n"); log(" enable debug output\n"); log("\n"); } void execute(std::vector args, RTLIL::Design *design) override { SimWorker worker; int numcycles = 20; log_header(design, "Executing SIM pass (simulate the circuit).\n"); size_t argidx; for (argidx = 1; argidx < args.size(); argidx++) { if (args[argidx] == "-vcd" && argidx+1 < args.size()) { std::string vcd_filename = args[++argidx]; rewrite_filename(vcd_filename); worker.vcdfile.open(vcd_filename.c_str()); continue; } if (args[argidx] == "-n" && argidx+1 < args.size()) { numcycles = atoi(args[++argidx].c_str()); continue; } if (args[argidx] == "-rstlen" && argidx+1 < args.size()) { worker.rstlen = atoi(args[++argidx].c_str()); continue; } if (args[argidx] == "-clock" && argidx+1 < args.size()) { worker.clock.insert(RTLIL::escape_id(args[++argidx])); continue; } if (args[argidx] == "-clockn" && argidx+1 < args.size()) { worker.clockn.insert(RTLIL::escape_id(args[++argidx])); continue; } if (args[argidx] == "-reset" && argidx+1 < args.size()) { worker.reset.insert(RTLIL::escape_id(args[++argidx])); continue; } if (args[argidx] == "-resetn" && argidx+1 < args.size()) { worker.resetn.insert(RTLIL::escape_id(args[++argidx])); continue; } if (args[argidx] == "-timescale" && argidx+1 < args.size()) { worker.timescale = args[++argidx]; continue; } if (args[argidx] == "-a") { worker.hide_internal = false; continue; } if (args[argidx] == "-d") { worker.debug = true; continue; } if (args[argidx] == "-w") { worker.writeback = true; continue; } if (args[argidx] == "-zinit") { worker.zinit = true; continue; } break; } extra_args(args, argidx, design); Module *top_mod = nullptr; if (design->full_selection()) { top_mod = design->top_module(); if (!top_mod) log_cmd_error("Design has no top module, use the 'hierarchy' command to specify one.\n"); } else { auto mods = design->selected_whole_modules(); if (GetSize(mods) != 1) log_cmd_error("Only one top module must be selected.\n"); top_mod = mods.front(); } worker.run(top_mod, numcycles); } } SimPass; PRIVATE_NAMESPACE_END