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author | David Shah <dave@ds0.me> | 2018-11-30 19:29:03 +0000 |
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committer | David Shah <dave@ds0.me> | 2019-01-22 16:02:56 +0000 |
commit | 549b8e74b2cef41a23e609bdb65c5b04b3141a61 (patch) | |
tree | 176f1964916c5c05580642f401689ab83946cbe5 /techlibs/ecp5/ecp5_ffinit.cc | |
parent | ee8c9e854f0b5f6500d030d4c700b29f042fb57f (diff) | |
download | yosys-549b8e74b2cef41a23e609bdb65c5b04b3141a61.tar.gz yosys-549b8e74b2cef41a23e609bdb65c5b04b3141a61.tar.bz2 yosys-549b8e74b2cef41a23e609bdb65c5b04b3141a61.zip |
ecp5: Support for flipflop initialisation
Signed-off-by: David Shah <dave@ds0.me>
Diffstat (limited to 'techlibs/ecp5/ecp5_ffinit.cc')
-rw-r--r-- | techlibs/ecp5/ecp5_ffinit.cc | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/techlibs/ecp5/ecp5_ffinit.cc b/techlibs/ecp5/ecp5_ffinit.cc new file mode 100644 index 000000000..02945fff4 --- /dev/null +++ b/techlibs/ecp5/ecp5_ffinit.cc @@ -0,0 +1,198 @@ +/* + * yosys -- Yosys Open SYnthesis Suite + * + * Copyright (C) 2012 Clifford Wolf <clifford@clifford.at> + * Copyright (C) 2018-19 David Shah <david@symbioticeda.com> + * + * 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" + +USING_YOSYS_NAMESPACE +PRIVATE_NAMESPACE_BEGIN + +struct Ecp5FfinitPass : public Pass { + Ecp5FfinitPass() : Pass("ecp5_ffinit", "ECP5: handle FF init values") { } + void help() YS_OVERRIDE + { + // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| + log("\n"); + log(" ecp5_ffinit [options] [selection]\n"); + log("\n"); + log("Remove init values for FF output signals when equal to reset value.\n"); + log("If reset is not used, set the reset value to the init value, otherwise\n"); + log("unmap out the reset (if not an async reset).\n"); + } + void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE + { + log_header(design, "Executing ECP5_FFINIT pass (implement FF init values).\n"); + + size_t argidx; + for (argidx = 1; argidx < args.size(); argidx++) + { + // if (args[argidx] == "-singleton") { + // singleton_mode = true; + // continue; + // } + break; + } + extra_args(args, argidx, design); + + for (auto module : design->selected_modules()) + { + log("Handling FF init values in %s.\n", log_id(module)); + + SigMap sigmap(module); + pool<Wire*> init_wires; + dict<SigBit, State> initbits; + dict<SigBit, SigBit> initbit_to_wire; + pool<SigBit> handled_initbits; + + for (auto wire : module->selected_wires()) + { + if (wire->attributes.count("\\init") == 0) + continue; + + SigSpec wirebits = sigmap(wire); + Const initval = wire->attributes.at("\\init"); + init_wires.insert(wire); + + for (int i = 0; i < GetSize(wirebits) && i < GetSize(initval); i++) + { + SigBit bit = wirebits[i]; + State val = initval[i]; + + if (val != State::S0 && val != State::S1) + continue; + + if (initbits.count(bit)) { + if (initbits.at(bit) != val) + log_error("Conflicting init values for signal %s (%s = %s, %s = %s).\n", + log_signal(bit), log_signal(SigBit(wire, i)), log_signal(val), + log_signal(initbit_to_wire[bit]), log_signal(initbits.at(bit))); + continue; + } + + initbits[bit] = val; + initbit_to_wire[bit] = SigBit(wire, i); + } + } + for (auto cell : module->selected_cells()) + { + if (cell->type != "\\TRELLIS_FF") + continue; + SigSpec sig_d = cell->getPort("\\DI"); + SigSpec sig_q = cell->getPort("\\Q"); + SigSpec sig_lsr = cell->getPort("\\LSR"); + + if (GetSize(sig_d) < 1 || GetSize(sig_q) < 1) + continue; + + SigBit bit_d = sigmap(sig_d[0]); + SigBit bit_q = sigmap(sig_q[0]); + + std::string regset = "RESET"; + if (cell->hasParam("\\REGSET")) + regset = cell->getParam("\\REGSET").decode_string(); + State resetState; + if (regset == "SET") + resetState = State::S1; + else if (regset == "RESET") + resetState = State::S0; + else + log_error("FF cell %s has illegal REGSET value %s.\n", + log_id(cell), regset.c_str()); + + if (!initbits.count(bit_q)) + continue; + + State val = initbits.at(bit_q); + + log("FF init value for cell %s (%s): %s = %c\n", log_id(cell), log_id(cell->type), + log_signal(bit_q), val != State::S0 ? '1' : '0'); + // Initval is the same as the reset state. Matches hardware, nowt more to do + if (val == resetState) { + handled_initbits.insert(bit_q); + continue; + } + + if (GetSize(sig_lsr) >= 1 && sig_lsr[0] != State::S0) { + std::string srmode = "LSR_OVER_CE"; + if (cell->hasParam("\\SRMODE")) + srmode = cell->getParam("\\SRMODE").decode_string(); + if (srmode == "ASYNC") { + log("Async reset value %c for FF cell %s inconsistent with init value %c.\n", + resetState != State::S0 ? '1' : '0', log_id(cell), val != State::S0 ? '1' : '0'); + } else { + SigBit bit_lsr = sigmap(sig_lsr[0]); + Wire *new_bit_d = module->addWire(NEW_ID); + if (resetState == State::S0) { + module->addAndnotGate(NEW_ID, bit_d, bit_lsr, new_bit_d); + } else { + module->addOrGate(NEW_ID, bit_d, bit_lsr, new_bit_d); + } + + cell->setPort("\\DI", new_bit_d); + cell->setPort("\\LSR", State::S0); + + if(cell->hasPort("\\CE")) { + std::string cemux = "CE"; + if (cell->hasParam("\\CEMUX")) + cemux = cell->getParam("\\CEMUX").decode_string(); + SigSpec sig_ce = cell->getPort("\\CE"); + if (GetSize(sig_ce) >= 1) { + SigBit bit_ce = sigmap(sig_ce[0]); + Wire *new_bit_ce = module->addWire(NEW_ID); + if (cemux == "INV") + module->addAndnotGate(NEW_ID, bit_ce, bit_lsr, new_bit_ce); + else + module->addOrGate(NEW_ID, bit_ce, bit_lsr, new_bit_ce); + cell->setPort("\\CE", new_bit_ce); + } + } + cell->setParam("\\REGSET", val != State::S0 ? Const("SET") : Const("RESET")); + handled_initbits.insert(bit_q); + } + } else { + cell->setParam("\\REGSET", val != State::S0 ? Const("SET") : Const("RESET")); + handled_initbits.insert(bit_q); + } + } + + for (auto wire : init_wires) + { + if (wire->attributes.count("\\init") == 0) + continue; + + SigSpec wirebits = sigmap(wire); + Const &initval = wire->attributes.at("\\init"); + bool remove_attribute = true; + + for (int i = 0; i < GetSize(wirebits) && i < GetSize(initval); i++) { + if (handled_initbits.count(wirebits[i])) + initval[i] = State::Sx; + else if (initval[i] != State::Sx) + remove_attribute = false; + } + + if (remove_attribute) + wire->attributes.erase("\\init"); + } + } + } +} Ecp5FfinitPass; + +PRIVATE_NAMESPACE_END |