From: Clifford Wolf <clifford@clifford.at>
Date: Fri, 14 Oct 2016 12:55:07 +0000 (+0200)
Subject: Added clk2fflogic
X-Git-Tag: yosys-0.7~29
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2733994aeba0879533cc1a871aae84497b32ff9e;p=yosys.git

Added clk2fflogic
---

diff --git a/passes/sat/Makefile.inc b/passes/sat/Makefile.inc
index 0c5f6fc60..6785b750a 100644
--- a/passes/sat/Makefile.inc
+++ b/passes/sat/Makefile.inc
@@ -5,4 +5,5 @@ OBJS += passes/sat/eval.o
 OBJS += passes/sat/miter.o
 OBJS += passes/sat/expose.o
 OBJS += passes/sat/assertpmux.o
+OBJS += passes/sat/clk2fflogic.o
 
diff --git a/passes/sat/clk2fflogic.cc b/passes/sat/clk2fflogic.cc
new file mode 100644
index 000000000..2934daadc
--- /dev/null
+++ b/passes/sat/clk2fflogic.cc
@@ -0,0 +1,153 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  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 Clk2fflogicPass : public Pass {
+	Clk2fflogicPass() : Pass("clk2fflogic", "convert clocked FFs to generic $ff cells") { }
+	virtual void help()
+	{
+		//   |---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");
+	}
+	virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+	{
+		// bool flag_noinit = false;
+
+		log_header(design, "Executing CLK2FFLOGIC pass (convert clocked FFs to generic $ff cells).\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			// if (args[argidx] == "-noinit") {
+			// 	flag_noinit = true;
+			// 	continue;
+			// }
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		for (auto module : design->selected_modules())
+		{
+			SigMap sigmap(module);
+			dict<SigBit, State> initbits;
+			pool<SigBit> del_initbits;
+			vector<Cell*> ffcells;
+
+			for (auto wire : module->wires())
+				if (wire->attributes.count("\\init") > 0)
+				{
+					Const initval = wire->attributes.at("\\init");
+					SigSpec initsig = sigmap(wire);
+
+					for (int i = 0; i < GetSize(initval) && i < GetSize(initsig); i++)
+						if (initval[i] == State::S0 || initval[i] == State::S1)
+							initbits[initsig[i]] = initval[i];
+				}
+
+			for (auto cell : module->selected_cells())
+				if (cell->type.in("$dff"))
+					ffcells.push_back(cell);
+
+			for (auto cell : ffcells)
+			{
+				if (cell->type == "$dff")
+				{
+					bool clkpol = cell->parameters["\\CLK_POLARITY"].as_bool();
+
+					SigSpec clk = cell->getPort("\\CLK");
+					SigSpec past_clk = module->addWire(NEW_ID);
+					module->addFf(NEW_ID, clk, past_clk);
+
+					SigSpec sig_d = cell->getPort("\\D");
+					SigSpec sig_q = cell->getPort("\\Q");
+
+					log("Replacing %s.%s (%s): CLK=%s, D=%s, Q=%s\n",
+							log_id(module), log_id(cell), log_id(cell->type),
+							log_signal(clk), log_signal(sig_d), log_signal(sig_q));
+					module->remove(cell);
+
+					SigSpec clock_edge = module->Eqx(NEW_ID, {past_clk, clk},
+							clkpol ? SigSpec({State::S0, State::S1}) : SigSpec({State::S1, State::S0}));
+
+					Wire *past_d = module->addWire(NEW_ID, GetSize(sig_d));
+					Wire *past_q = module->addWire(NEW_ID, GetSize(sig_q));
+					module->addFf(NEW_ID, sig_d, past_d);
+					module->addFf(NEW_ID, sig_q, past_q);
+
+					module->addMux(NEW_ID, past_q, past_d, clock_edge, sig_q);
+
+					Const initval;
+					bool assign_initval = false;
+					for (int i = 0; i < GetSize(sig_d); i++) {
+						SigBit qbit = sigmap(sig_q[i]);
+						if (initbits.count(qbit)) {
+							initval.bits.push_back(initbits.at(qbit));
+							del_initbits.insert(qbit);
+						} else
+							initval.bits.push_back(State::Sx);
+						if (initval.bits.back() != State::Sx)
+							assign_initval = true;
+					}
+
+					if (assign_initval) {
+						past_d->attributes["\\init"] = initval;
+						past_q->attributes["\\init"] = initval;
+					}
+
+					continue;
+				}
+
+				log_abort();
+			}
+
+			for (auto wire : module->wires())
+				if (wire->attributes.count("\\init") > 0)
+				{
+					bool delete_initattr = true;
+					Const initval = wire->attributes.at("\\init");
+					SigSpec initsig = sigmap(wire);
+
+					for (int i = 0; i < GetSize(initval) && i < GetSize(initsig); i++)
+						if (del_initbits.count(initsig[i]) > 0)
+							initval[i] = State::Sx;
+						else if (initval[i] != State::Sx)
+							delete_initattr = false;
+
+					if (delete_initattr)
+						wire->attributes.erase("\\init");
+					else
+						wire->attributes.at("\\init") = initval;
+				}
+		}
+
+	}
+} Clk2fflogicPass;
+
+PRIVATE_NAMESPACE_END