riscv
/
yosys
mirror of https://github.com/YosysHQ/yosys.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
yosys/passes/sat/clk2fflogic.cc

278 lines
9.9 KiB
C++
Raw Blame History

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Claire Xenia Wolf <claire@yosyshq.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"
#include "kernel/ffinit.h"
#include "kernel/ff.h"
#include "kernel/mem.h"
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
struct Clk2fflogicPass : public Pass {
Clk2fflogicPass() : Pass("clk2fflogic", "convert clocked FFs to generic $ff cells") { }
void help() override
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" clk2fflogic [options] [selection]\n");
log("\n");
log("This command replaces clocked flip-flops with generic $ff cells that use the\n");
log("implicit global clock. This is useful for formal verification of designs with\n");
log("multiple clocks.\n");
log("\n");
}
SigSpec wrap_async_control(Module *module, SigSpec sig, bool polarity, bool is_fine, IdString past_sig_id) {
if (!is_fine)
return wrap_async_control(module, sig, polarity, past_sig_id);
return wrap_async_control_gate(module, sig, polarity, past_sig_id);
}
SigSpec wrap_async_control(Module *module, SigSpec sig, bool polarity, IdString past_sig_id) {
Wire *past_sig = module->addWire(past_sig_id, GetSize(sig));
past_sig->attributes[ID::init] = RTLIL::Const(polarity ? State::S0 : State::S1, GetSize(sig));
module->addFf(NEW_ID, sig, past_sig);
if (polarity)
sig = module->Or(NEW_ID, sig, past_sig);
else
sig = module->And(NEW_ID, sig, past_sig);
if (polarity)
return sig;
else
return module->Not(NEW_ID, sig);
}
SigSpec wrap_async_control_gate(Module *module, SigSpec sig, bool polarity, IdString past_sig_id) {
Wire *past_sig = module->addWire(past_sig_id);
past_sig->attributes[ID::init] = polarity ? State::S0 : State::S1;
module->addFfGate(NEW_ID, sig, past_sig);
if (polarity)
sig = module->OrGate(NEW_ID, sig, past_sig);
else
sig = module->AndGate(NEW_ID, sig, past_sig);
if (polarity)
return sig;
else
return module->NotGate(NEW_ID, sig);
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override
{
// bool flag_noinit = false;
log_header(design, "Executing CLK2FFLOGIC pass (convert clocked FFs to generic $ff cells).\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
// if (args[argidx] == "-noinit") {
// flag_noinit = true;
// continue;
// }
break;
}
extra_args(args, argidx, design);
for (auto module : design->selected_modules())
{
SigMap sigmap(module);
FfInitVals initvals(&sigmap, module);
for (auto &mem : Mem::get_selected_memories(module))
{
for (int i = 0; i < GetSize(mem.rd_ports); i++) {
auto &port = mem.rd_ports[i];
if (port.clk_enable)
log_error("Read port %d of memory %s.%s is clocked. This is not supported by \"clk2fflogic\"! "
"Call \"memory\" with -nordff to avoid this error.\n", i, log_id(mem.memid), log_id(module));
}
for (int i = 0; i < GetSize(mem.wr_ports); i++)
{
auto &port = mem.wr_ports[i];
if (!port.clk_enable)
continue;
log("Modifying write port %d on memory %s.%s: CLK=%s, A=%s, D=%s\n",
i, log_id(module), log_id(mem.memid), log_signal(port.clk),
log_signal(port.addr), log_signal(port.data));
Wire *past_clk = module->addWire(NEW_ID_SUFFIX(stringf("%s#%d#past_clk#%s", log_id(mem.memid), i, log_signal(port.clk))));
past_clk->attributes[ID::init] = port.clk_polarity ? State::S1 : State::S0;
module->addFf(NEW_ID, port.clk, past_clk);
SigSpec clock_edge_pattern;
if (port.clk_polarity) {
clock_edge_pattern.append(State::S0);
clock_edge_pattern.append(State::S1);
} else {
clock_edge_pattern.append(State::S1);
clock_edge_pattern.append(State::S0);
}
SigSpec clock_edge = module->Eqx(NEW_ID, {port.clk, SigSpec(past_clk)}, clock_edge_pattern);
SigSpec en_q = module->addWire(NEW_ID_SUFFIX(stringf("%s#%d#en_q", log_id(mem.memid), i)), GetSize(port.en));
module->addFf(NEW_ID, port.en, en_q);
SigSpec addr_q = module->addWire(NEW_ID_SUFFIX(stringf("%s#%d#addr_q", log_id(mem.memid), i)), GetSize(port.addr));
module->addFf(NEW_ID, port.addr, addr_q);
SigSpec data_q = module->addWire(NEW_ID_SUFFIX(stringf("%s#%d#data_q", log_id(mem.memid), i)), GetSize(port.data));
module->addFf(NEW_ID, port.data, data_q);
port.clk = State::S0;
port.en = module->Mux(NEW_ID, Const(0, GetSize(en_q)), en_q, clock_edge);
port.addr = addr_q;
port.data = data_q;
port.clk_enable = false;
port.clk_polarity = false;
}
mem.emit();
}
for (auto cell : vector<Cell*>(module->selected_cells()))
{
SigSpec qval;
if (RTLIL::builtin_ff_cell_types().count(cell->type)) {
FfData ff(&initvals, cell);
if (ff.has_gclk) {
// Already a $ff or $_FF_ cell.
continue;
}
if (ff.has_clk) {
log("Replacing %s.%s (%s): CLK=%s, D=%s, Q=%s\n",
log_id(module), log_id(cell), log_id(cell->type),
log_signal(ff.sig_clk), log_signal(ff.sig_d), log_signal(ff.sig_q));
} else if (ff.has_aload) {
log("Replacing %s.%s (%s): EN=%s, D=%s, Q=%s\n",
log_id(module), log_id(cell), log_id(cell->type),
log_signal(ff.sig_aload), log_signal(ff.sig_ad), log_signal(ff.sig_q));
} else {
// $sr.
log("Replacing %s.%s (%s): SET=%s, CLR=%s, Q=%s\n",
log_id(module), log_id(cell), log_id(cell->type),
log_signal(ff.sig_set), log_signal(ff.sig_clr), log_signal(ff.sig_q));
}
ff.remove();
// Strip spaces from signal name, since Yosys IDs can't contain spaces
// Spaces only occur when we have a signal that's a slice of a larger bus,
// e.g. "\myreg [5:0]", so removing spaces shouldn't result in loss of uniqueness
std::string sig_q_str = log_signal(ff.sig_q);
sig_q_str.erase(std::remove(sig_q_str.begin(), sig_q_str.end(), ' '), sig_q_str.end());
Wire *past_q = module->addWire(NEW_ID_SUFFIX(stringf("%s#past_q_wire", sig_q_str.c_str())), ff.width);
if (!ff.is_fine) {
module->addFf(NEW_ID, ff.sig_q, past_q);
} else {
module->addFfGate(NEW_ID, ff.sig_q, past_q);
}
if (!ff.val_init.is_fully_undef())
initvals.set_init(past_q, ff.val_init);
if (ff.has_clk) {
ff.unmap_ce_srst();
Wire *past_clk = module->addWire(NEW_ID_SUFFIX(stringf("%s#past_clk#%s", sig_q_str.c_str(), log_signal(ff.sig_clk))));
initvals.set_init(past_clk, ff.pol_clk ? State::S1 : State::S0);
if (!ff.is_fine)
module->addFf(NEW_ID, ff.sig_clk, past_clk);
else
module->addFfGate(NEW_ID, ff.sig_clk, past_clk);
SigSpec clock_edge_pattern;
if (ff.pol_clk) {
clock_edge_pattern.append(State::S0);
clock_edge_pattern.append(State::S1);
} else {
clock_edge_pattern.append(State::S1);
clock_edge_pattern.append(State::S0);
}
SigSpec clock_edge = module->Eqx(NEW_ID, {ff.sig_clk, SigSpec(past_clk)}, clock_edge_pattern);
Wire *past_d = module->addWire(NEW_ID_SUFFIX(stringf("%s#past_d_wire", sig_q_str.c_str())), ff.width);
if (!ff.is_fine)
module->addFf(NEW_ID, ff.sig_d, past_d);
else
module->addFfGate(NEW_ID, ff.sig_d, past_d);
if (!ff.val_init.is_fully_undef())
initvals.set_init(past_d, ff.val_init);
if (!ff.is_fine)
qval = module->Mux(NEW_ID, past_q, past_d, clock_edge);
else
qval = module->MuxGate(NEW_ID, past_q, past_d, clock_edge);
} else {
qval = past_q;
}
// The check for a constant sig_aload is also done by opt_dff, but when using verific and running
// clk2fflogic before opt_dff (which does more and possibly unwanted optimizations) this check avoids
// generating a lot of extra logic.
if (ff.has_aload && ff.sig_aload != (ff.pol_aload ? State::S0 : State::S1)) {
SigSpec sig_aload = wrap_async_control(module, ff.sig_aload, ff.pol_aload, ff.is_fine, NEW_ID);
if (!ff.is_fine)
qval = module->Mux(NEW_ID, qval, ff.sig_ad, sig_aload);
else
qval = module->MuxGate(NEW_ID, qval, ff.sig_ad, sig_aload);
}
if (ff.has_sr) {
SigSpec setval = wrap_async_control(module, ff.sig_set, ff.pol_set, ff.is_fine, NEW_ID);
SigSpec clrval = wrap_async_control(module, ff.sig_clr, ff.pol_clr, ff.is_fine, NEW_ID);
if (!ff.is_fine) {
clrval = module->Not(NEW_ID, clrval);
qval = module->Or(NEW_ID, qval, setval);
module->addAnd(NEW_ID, qval, clrval, ff.sig_q);
} else {
clrval = module->NotGate(NEW_ID, clrval);
qval = module->OrGate(NEW_ID, qval, setval);
module->addAndGate(NEW_ID, qval, clrval, ff.sig_q);
}
} else if (ff.has_arst) {
IdString id = NEW_ID_SUFFIX(stringf("%s#past_arst#%s", sig_q_str.c_str(), log_signal(ff.sig_arst)));
SigSpec arst = wrap_async_control(module, ff.sig_arst, ff.pol_arst, ff.is_fine, id);
if (!ff.is_fine)
module->addMux(NEW_ID, qval, ff.val_arst, arst, ff.sig_q);
else
module->addMuxGate(NEW_ID, qval, ff.val_arst[0], arst, ff.sig_q);
} else {
module->connect(ff.sig_q, qval);
}
}
}
}
}
} Clk2fflogicPass;
PRIVATE_NAMESPACE_END
Reference in New Issue View Git Blame Copy Permalink