passes/sat/clk2fflogic.cc

   1 /*
   2  *  yosys -- Yosys Open SYnthesis Suite
   3  *
   4  *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
   5  *
   6  *  Permission to use, copy, modify, and/or distribute this software for any
   7  *  purpose with or without fee is hereby granted, provided that the above
   8  *  copyright notice and this permission notice appear in all copies.
   9  *
  10  *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  *
  18  */
  19
  20 #include "kernel/yosys.h"
  21 #include "kernel/sigtools.h"
  22
  23 USING_YOSYS_NAMESPACE
  24 PRIVATE_NAMESPACE_BEGIN
  25
  26 struct Clk2fflogicPass : public Pass {
  27         Clk2fflogicPass() : Pass("clk2fflogic", "convert clocked FFs to generic $ff cells") { }
  28         virtual void help()
  29         {
  30                 //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
  31                 log("\n");
  32                 log("    clk2fflogic [options] [selection]\n");
  33                 log("\n");
  34                 log("This command replaces clocked flip-flops with generic $ff cells that use the\n");
  35                 log("implicit global clock. This is useful for formal verification of designs with\n");
  36                 log("multiple clocks.\n");
  37                 log("\n");
  38         }
  39         virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
  40         {
  41                 // bool flag_noinit = false;
  42
  43                 log_header(design, "Executing CLK2FFLOGIC pass (convert clocked FFs to generic $ff cells).\n");
  44
  45                 size_t argidx;
  46                 for (argidx = 1; argidx < args.size(); argidx++)
  47                 {
  48                         // if (args[argidx] == "-noinit") {
  49                         //      flag_noinit = true;
  50                         //      continue;
  51                         // }
  52                         break;
  53                 }
  54                 extra_args(args, argidx, design);
  55
  56                 for (auto module : design->selected_modules())
  57                 {
  58                         SigMap sigmap(module);
  59                         dict<SigBit, State> initbits;
  60                         pool<SigBit> del_initbits;
  61
  62                         for (auto wire : module->wires())
  63                                 if (wire->attributes.count("\\init") > 0)
  64                                 {
  65                                         Const initval = wire->attributes.at("\\init");
  66                                         SigSpec initsig = sigmap(wire);
  67
  68                                         for (int i = 0; i < GetSize(initval) && i < GetSize(initsig); i++)
  69                                                 if (initval[i] == State::S0 || initval[i] == State::S1)
  70                                                         initbits[initsig[i]] = initval[i];
  71                                 }
  72
  73                         for (auto cell : vector<Cell*>(module->selected_cells()))
  74                         {
  75                                 if (cell->type.in("$mem"))
  76                                 {
  77                                         int abits = cell->getParam("\\ABITS").as_int();
  78                                         int width = cell->getParam("\\WIDTH").as_int();
  79                                         int rd_ports = cell->getParam("\\RD_PORTS").as_int();
  80                                         int wr_ports = cell->getParam("\\WR_PORTS").as_int();
  81
  82                                         for (int i = 0; i < rd_ports; i++) {
  83                                                 if (cell->getParam("\\RD_CLK_ENABLE").extract(i).as_bool())
  84                                                         log_error("Read port %d of memory %s.%s is clocked. This is not supported by \"clk2fflogic\"! "
  85                                                                         "Call \"memory\" with -nordff to avoid this error.\n", i, log_id(cell), log_id(module));
  86                                         }
  87
  88                                         Const wr_clk_en_param = cell->getParam("\\WR_CLK_ENABLE");
  89                                         Const wr_clk_pol_param = cell->getParam("\\WR_CLK_POLARITY");
  90
  91                                         SigSpec wr_clk_port = cell->getPort("\\WR_CLK");
  92                                         SigSpec wr_en_port = cell->getPort("\\WR_EN");
  93                                         SigSpec wr_addr_port = cell->getPort("\\WR_ADDR");
  94                                         SigSpec wr_data_port = cell->getPort("\\WR_DATA");
  95
  96                                         for (int wport = 0; wport < wr_ports; wport++)
  97                                         {
  98                                                 bool clken = wr_clk_en_param[wport] == State::S1;
  99                                                 bool clkpol = wr_clk_pol_param[wport] == State::S1;
 100
 101                                                 if (!clken)
 102                                                         continue;
 103
 104                                                 SigBit clk = wr_clk_port[wport];
 105                                                 SigSpec en = wr_en_port.extract(wport*width, width);
 106                                                 SigSpec addr = wr_addr_port.extract(wport*abits, abits);
 107                                                 SigSpec data = wr_data_port.extract(wport*width, width);
 108
 109                                                 log("Modifying write port %d on memory %s.%s: CLK=%s, A=%s, D=%s\n",
 110                                                                 wport, log_id(module), log_id(cell), log_signal(clk),
 111                                                                 log_signal(addr), log_signal(data));
 112
 113                                                 Wire *past_clk = module->addWire(NEW_ID);
 114                                                 past_clk->attributes["\\init"] = clkpol ? State::S1 : State::S0;
 115                                                 module->addFf(NEW_ID, clk, past_clk);
 116
 117                                                 SigSpec clock_edge_pattern;
 118
 119                                                 if (clkpol) {
 120                                                         clock_edge_pattern.append_bit(State::S0);
 121                                                         clock_edge_pattern.append_bit(State::S1);
 122                                                 } else {
 123                                                         clock_edge_pattern.append_bit(State::S1);
 124                                                         clock_edge_pattern.append_bit(State::S0);
 125                                                 }
 126
 127                                                 SigSpec clock_edge = module->Eqx(NEW_ID, {clk, SigSpec(past_clk)}, clock_edge_pattern);
 128
 129                                                 SigSpec en_q = module->addWire(NEW_ID, GetSize(en));
 130                                                 module->addFf(NEW_ID, en, en_q);
 131
 132                                                 SigSpec addr_q = module->addWire(NEW_ID, GetSize(addr));
 133                                                 module->addFf(NEW_ID, addr, addr_q);
 134
 135                                                 SigSpec data_q = module->addWire(NEW_ID, GetSize(data));
 136                                                 module->addFf(NEW_ID, data, data_q);
 137
 138                                                 wr_clk_port[wport] = State::S0;
 139                                                 wr_en_port.replace(wport*width, module->Mux(NEW_ID, Const(0, GetSize(en_q)), en_q, clock_edge));
 140                                                 wr_addr_port.replace(wport*abits, addr_q);
 141                                                 wr_data_port.replace(wport*width, data_q);
 142
 143                                                 wr_clk_en_param[wport] = State::S0;
 144                                                 wr_clk_pol_param[wport] = State::S0;
 145                                         }
 146
 147                                         cell->setParam("\\WR_CLK_ENABLE", wr_clk_en_param);
 148                                         cell->setParam("\\WR_CLK_POLARITY", wr_clk_pol_param);
 149
 150                                         cell->setPort("\\WR_CLK", wr_clk_port);
 151                                         cell->setPort("\\WR_EN", wr_en_port);
 152                                         cell->setPort("\\WR_ADDR", wr_addr_port);
 153                                         cell->setPort("\\WR_DATA", wr_data_port);
 154                                 }
 155
 156                                 if (cell->type.in("$dlatch"))
 157                                 {
 158                                         bool enpol = cell->parameters["\\EN_POLARITY"].as_bool();
 159
 160                                         SigSpec sig_en = cell->getPort("\\EN");
 161                                         SigSpec sig_d = cell->getPort("\\D");
 162                                         SigSpec sig_q = cell->getPort("\\Q");
 163
 164                                         log("Replacing %s.%s (%s): EN=%s, D=%s, Q=%s\n",
 165                                                         log_id(module), log_id(cell), log_id(cell->type),
 166                                                         log_signal(sig_en), log_signal(sig_d), log_signal(sig_q));
 167
 168                                         Wire *past_q = module->addWire(NEW_ID, GetSize(sig_q));
 169                                         module->addFf(NEW_ID, sig_q, past_q);
 170
 171                                         if (enpol)
 172                                                 module->addMux(NEW_ID, past_q, sig_d, sig_en, sig_q);
 173                                         else
 174                                                 module->addMux(NEW_ID, sig_d, past_q, sig_en, sig_q);
 175
 176                                         Const initval;
 177                                         bool assign_initval = false;
 178                                         for (int i = 0; i < GetSize(sig_d); i++) {
 179                                                 SigBit qbit = sigmap(sig_q[i]);
 180                                                 if (initbits.count(qbit)) {
 181                                                         initval.bits.push_back(initbits.at(qbit));
 182                                                         del_initbits.insert(qbit);
 183                                                 } else
 184                                                         initval.bits.push_back(State::Sx);
 185                                                 if (initval.bits.back() != State::Sx)
 186                                                         assign_initval = true;
 187                                         }
 188
 189                                         if (assign_initval)
 190                                                 past_q->attributes["\\init"] = initval;
 191
 192                                         module->remove(cell);
 193                                         continue;
 194                                 }
 195
 196                                 if (cell->type.in("$dff", "$adff", "$dffsr"))
 197                                 {
 198                                         bool clkpol = cell->parameters["\\CLK_POLARITY"].as_bool();
 199
 200                                         SigSpec clk = cell->getPort("\\CLK");
 201                                         Wire *past_clk = module->addWire(NEW_ID);
 202                                         past_clk->attributes["\\init"] = clkpol ? State::S1 : State::S0;
 203                                         module->addFf(NEW_ID, clk, past_clk);
 204
 205                                         SigSpec sig_d = cell->getPort("\\D");
 206                                         SigSpec sig_q = cell->getPort("\\Q");
 207
 208                                         log("Replacing %s.%s (%s): CLK=%s, D=%s, Q=%s\n",
 209                                                         log_id(module), log_id(cell), log_id(cell->type),
 210                                                         log_signal(clk), log_signal(sig_d), log_signal(sig_q));
 211
 212                                         SigSpec clock_edge_pattern;
 213
 214                                         if (clkpol) {
 215                                                 clock_edge_pattern.append_bit(State::S0);
 216                                                 clock_edge_pattern.append_bit(State::S1);
 217                                         } else {
 218                                                 clock_edge_pattern.append_bit(State::S1);
 219                                                 clock_edge_pattern.append_bit(State::S0);
 220                                         }
 221
 222                                         SigSpec clock_edge = module->Eqx(NEW_ID, {clk, SigSpec(past_clk)}, clock_edge_pattern);
 223
 224                                         Wire *past_d = module->addWire(NEW_ID, GetSize(sig_d));
 225                                         Wire *past_q = module->addWire(NEW_ID, GetSize(sig_q));
 226                                         module->addFf(NEW_ID, sig_d, past_d);
 227                                         module->addFf(NEW_ID, sig_q, past_q);
 228
 229                                         if (cell->type == "$adff")
 230                                         {
 231                                                 SigSpec arst = cell->getPort("\\ARST");
 232                                                 SigSpec qval = module->Mux(NEW_ID, past_q, past_d, clock_edge);
 233                                                 Const rstval = cell->parameters["\\ARST_VALUE"];
 234
 235                                                 if (cell->parameters["\\ARST_POLARITY"].as_bool())
 236                                                         module->addMux(NEW_ID, qval, rstval, arst, sig_q);
 237                                                 else
 238                                                         module->addMux(NEW_ID, rstval, qval, arst, sig_q);
 239                                         }
 240                                         else
 241                                         if (cell->type == "$dffsr")
 242                                         {
 243                                                 SigSpec qval = module->Mux(NEW_ID, past_q, past_d, clock_edge);
 244                                                 SigSpec setval = cell->getPort("\\SET");
 245                                                 SigSpec clrval = cell->getPort("\\CLR");
 246
 247                                                 if (!cell->parameters["\\SET_POLARITY"].as_bool())
 248                                                         setval = module->Not(NEW_ID, setval);
 249
 250                                                 if (cell->parameters["\\CLR_POLARITY"].as_bool())
 251                                                         clrval = module->Not(NEW_ID, clrval);
 252
 253                                                 qval = module->Or(NEW_ID, qval, setval);
 254                                                 module->addAnd(NEW_ID, qval, clrval, sig_q);
 255                                         }
 256                                         else
 257                                         {
 258                                                 module->addMux(NEW_ID, past_q, past_d, clock_edge, sig_q);
 259                                         }
 260
 261                                         Const initval;
 262                                         bool assign_initval = false;
 263                                         for (int i = 0; i < GetSize(sig_d); i++) {
 264                                                 SigBit qbit = sigmap(sig_q[i]);
 265                                                 if (initbits.count(qbit)) {
 266                                                         initval.bits.push_back(initbits.at(qbit));
 267                                                         del_initbits.insert(qbit);
 268                                                 } else
 269                                                         initval.bits.push_back(State::Sx);
 270                                                 if (initval.bits.back() != State::Sx)
 271                                                         assign_initval = true;
 272                                         }
 273
 274                                         if (assign_initval) {
 275                                                 past_d->attributes["\\init"] = initval;
 276                                                 past_q->attributes["\\init"] = initval;
 277                                         }
 278
 279                                         module->remove(cell);
 280                                         continue;
 281                                 }
 282                         }
 283
 284                         for (auto wire : module->wires())
 285                                 if (wire->attributes.count("\\init") > 0)
 286                                 {
 287                                         bool delete_initattr = true;
 288                                         Const initval = wire->attributes.at("\\init");
 289                                         SigSpec initsig = sigmap(wire);
 290
 291                                         for (int i = 0; i < GetSize(initval) && i < GetSize(initsig); i++)
 292                                                 if (del_initbits.count(initsig[i]) > 0)
 293                                                         initval[i] = State::Sx;
 294                                                 else if (initval[i] != State::Sx)
 295                                                         delete_initattr = false;
 296
 297                                         if (delete_initattr)
 298                                                 wire->attributes.erase("\\init");
 299                                         else
 300                                                 wire->attributes.at("\\init") = initval;
 301                                 }
 302                 }
 303
 304         }
 305 } Clk2fflogicPass;
 306
 307 PRIVATE_NAMESPACE_END