Refactor SF2 iobuf insertion, Add clkint insertion

Signed-off-by: Clifford Wolf <clifford@clifford.at>

examples/igloo2/runme.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 set -ex
-yosys -p 'synth_sf2 -noclkbuf -top example -edif netlist.edn -vlog netlist.vm' example.v
+yosys -p 'synth_sf2 -top example -edif netlist.edn -vlog netlist.vm' example.v
 export LM_LICENSE_FILE=${LM_LICENSE_FILE:-1702@localhost}
 /opt/microsemi/Libero_SoC_v12.0/Libero/bin/libero SCRIPT:libero.tcl
 cp proj/designer/example/export/example.stp .

techlibs/sf2/cells_sim.v

@@ -74,6 +74,13 @@ module CFG4 (
 	assign Y = INIT >> {D, C, B, A};
 endmodule
 
+module CLKINT (
+	input A,
+	output Y
+);
+	assign Y = A;
+endmodule
+
 module CLKBUF (
 	input PAD,
 	output Y

techlibs/sf2/sf2_iobs.cc

@@ -23,6 +23,136 @@
 USING_YOSYS_NAMESPACE
 PRIVATE_NAMESPACE_BEGIN
 
+static void handle_iobufs(Module *module, bool clkbuf_mode)
+{
+	SigMap sigmap(module);
+
+	pool<SigBit> clk_bits;
+	pool<SigBit> handled_io_bits;
+	dict<SigBit, SigBit> rewrite_bits;
+	vector<pair<Cell*, SigBit>> pad_bits;
+
+	for (auto cell : module->cells())
+	{
+		if (clkbuf_mode && cell->type == "\\SLE") {
+			for (auto bit : sigmap(cell->getPort("\\CLK")))
+				clk_bits.insert(bit);
+		}
+		if (cell->type.in("\\INBUF", "\\OUTBUF", "\\TRIBUF", "\\BIBUF", "\\CLKBUF", "\\CLKBIBUF",
+				"\\INBUF_DIFF", "\\OUTBUF_DIFF", "\\BIBUFF_DIFF", "\\TRIBUF_DIFF", "\\CLKBUF_DIFF",
+				"\\GCLKBUF", "\\GCLKBUF_DIFF", "\\GCLKBIBUF")) {
+			for (auto bit : sigmap(cell->getPort("\\PAD")))
+				handled_io_bits.insert(bit);
+		}
+	}
+
+	for (auto wire : vector<Wire*>(module->wires()))
+	{
+		if (!wire->port_input && !wire->port_output)
+			continue;
+
+		for (int index = 0; index < GetSize(wire); index++)
+		{
+			SigBit bit(wire, index);
+			SigBit canonical_bit = sigmap(bit);
+
+			if (handled_io_bits.count(canonical_bit))
+				continue;
+
+			if (wire->port_input && wire->port_output)
+				log_error("Failed to add buffer for inout port bit %s.\n", log_signal(bit));
+
+			IdString buf_type, buf_port;
+
+			if (wire->port_output) {
+				buf_type = "\\OUTBUF";
+				buf_port = "\\D";
+			} else if (clkbuf_mode && clk_bits.count(canonical_bit)) {
+				buf_type = "\\CLKBUF";
+				buf_port = "\\Y";
+			} else {
+				buf_type = "\\INBUF";
+				buf_port = "\\Y";
+			}
+
+			Cell *c = module->addCell(NEW_ID, buf_type);
+			SigBit new_bit = module->addWire(NEW_ID);
+			c->setPort(buf_port, new_bit);
+			pad_bits.push_back(make_pair(c, bit));
+			rewrite_bits[canonical_bit] = new_bit;
+
+			log("Added %s cell %s for port bit %s.\n", log_id(c->type), log_id(c), log_signal(bit));
+		}
+	}
+
+	auto rewrite_function = [&](SigSpec &s) {
+		for (auto &bit : s) {
+			SigBit canonical_bit = sigmap(bit);
+			if (rewrite_bits.count(canonical_bit))
+				bit = rewrite_bits.at(canonical_bit);
+		}
+	};
+
+	module->rewrite_sigspecs(rewrite_function);
+
+	for (auto &it : pad_bits)
+		it.first->setPort("\\PAD", it.second);
+}
+
+static void handle_clkint(Module *module)
+{
+	SigMap sigmap(module);
+
+	pool<SigBit> clk_bits;
+	vector<SigBit> handled_clk_bits;
+
+	for (auto cell : module->cells())
+	{
+		if (cell->type == "\\SLE") {
+			for (auto bit : sigmap(cell->getPort("\\CLK")))
+				clk_bits.insert(bit);
+		}
+		if (cell->type.in("\\CLKBUF", "\\CLKBIBUF", "\\CLKBUF_DIFF", "\\GCLKBUF", "\\GCLKBUF_DIFF", "\\GCLKBIBUF",
+				"\\CLKINT", "\\CLKINT_PRESERVE", "\\GCLKINT", "\\RCLKINT", "\\RGCLKINT")) {
+			for (auto bit : sigmap(cell->getPort("\\Y")))
+				handled_clk_bits.push_back(bit);
+		}
+	}
+
+	for (auto bit : handled_clk_bits)
+		clk_bits.erase(bit);
+
+	for (auto cell : vector<Cell*>(module->cells()))
+	for (auto &conn : cell->connections())
+	{
+		if (!cell->output(conn.first))
+			continue;
+
+		SigSpec sig = conn.second;
+		bool did_something = false;
+
+		for (auto &bit : sig) {
+			SigBit canonical_bit = sigmap(bit);
+			if (clk_bits.count(canonical_bit)) {
+				Cell *c = module->addCell(NEW_ID, "\\CLKINT");
+				SigBit new_bit = module->addWire(NEW_ID);
+				c->setPort("\\A", new_bit);
+				c->setPort("\\Y", bit);
+				log("Added %s cell %s for clock signal %s.\n", log_id(c->type), log_id(c), log_signal(bit));
+				clk_bits.erase(canonical_bit);
+				did_something = true;
+				bit = new_bit;
+			}
+		}
+
+		if (did_something)
+			cell->setPort(conn.first, sig);
+	}
+
+	for (auto bit : clk_bits)
+		log_error("Failed to insert CLKINT for clock signal %s.\n", log_signal(bit));
+}
+
 struct Sf2IobsPass : public Pass {
 	Sf2IobsPass() : Pass("sf2_iobs", "SF2: insert IO buffers") { }
 	void help() YS_OVERRIDE
@@ -31,23 +161,23 @@ struct Sf2IobsPass : public Pass {
 		log("\n");
 		log("    sf2_iobs [options] [selection]\n");
 		log("\n");
-		log("Add SF2 I/O buffers to top module IOs as needed.\n");
+		log("Add SF2 I/O buffers and global buffers to top module as needed.\n");
 		log("\n");
-		log("    -noclkbuf\n");
+		log("    -clkbuf\n");
-		log("        Do not insert clock buffers\n");
+		log("        Insert PAD->global_net clock buffers\n");
 		log("\n");
 	}
 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
 	{
-		bool noclkbuf_mode = false;
+		bool clkbuf_mode = false;
 
 		log_header(design, "Executing sf2_iobs pass (insert IO buffers).\n");
 
 		size_t argidx;
 		for (argidx = 1; argidx < args.size(); argidx++)
 		{
-			if (args[argidx] == "-noclkbuf") {
+			if (args[argidx] == "-clkbuf") {
-				noclkbuf_mode = true;
+				clkbuf_mode = true;
 				continue;
 			}
 			break;
@@ -59,76 +189,8 @@ struct Sf2IobsPass : public Pass {
 		if (module == nullptr)
 			log_cmd_error("No top module found.\n");
 
-		SigMap sigmap(module);
+		handle_iobufs(module, clkbuf_mode);
-
+		handle_clkint(module);
-		pool<SigBit> clk_bits;
-		pool<SigBit> handled_io_bits;
-		dict<SigBit, SigBit> rewrite_bits;
-		vector<pair<Cell*, SigBit>> pad_bits;
-
-		for (auto cell : module->cells())
-		{
-			if (cell->type == "\\SLE") {
-				for (auto bit : sigmap(cell->getPort("\\CLK")))
-					clk_bits.insert(bit);
-			}
-			if (cell->type.in("\\INBUF", "\\OUTBUF", "\\CLKBUF")) {
-				for (auto bit : sigmap(cell->getPort("\\PAD")))
-					handled_io_bits.insert(bit);
-			}
-		}
-
-		for (auto wire : vector<Wire*>(module->wires()))
-		{
-			if (!wire->port_input && !wire->port_output)
-				continue;
-
-			for (int index = 0; index < GetSize(wire); index++)
-			{
-				SigBit bit(wire, index);
-				SigBit canonical_bit = sigmap(bit);
-
-				if (handled_io_bits.count(canonical_bit))
-					continue;
-
-				if (wire->port_input && wire->port_output)
-					log_error("Failed to add buffer for inout port bit %s.\n", log_signal(bit));
-
-				IdString buf_type, buf_port;
-
-				if (wire->port_output) {
-					buf_type = "\\OUTBUF";
-					buf_port = "\\D";
-				} else if (clk_bits.count(canonical_bit) && !noclkbuf_mode) {
-					buf_type = "\\CLKBUF";
-					buf_port = "\\Y";
-				} else {
-					buf_type = "\\INBUF";
-					buf_port = "\\Y";
-				}
-
-				Cell *c = module->addCell(NEW_ID, buf_type);
-				SigBit new_bit = module->addWire(NEW_ID);
-				c->setPort(buf_port, new_bit);
-				pad_bits.push_back(make_pair(c, bit));
-				rewrite_bits[canonical_bit] = new_bit;
-
-				log("Added %s cell %s for port bit %s.\n", log_id(c->type), log_id(c), log_signal(bit));
-			}
-		}
-
-		auto rewrite_function = [&](SigSpec &s) {
-			for (auto &bit : s) {
-				SigBit canonical_bit = sigmap(bit);
-				if (rewrite_bits.count(canonical_bit))
-					bit = rewrite_bits.at(canonical_bit);
-			}
-		};
-
-		module->rewrite_sigspecs(rewrite_function);
-
-		for (auto &it : pad_bits)
-			it.first->setPort("\\PAD", it.second);
 	}
 } Sf2IobsPass;
 

techlibs/sf2/synth_sf2.cc

@@ -63,8 +63,8 @@ struct SynthSf2Pass : public ScriptPass
 		log("    -noiobs\n");
 		log("        run synthesis in \"block mode\", i.e. do not insert IO buffers\n");
 		log("\n");
-		log("    -noclkbuf\n");
+		log("    -clkbuf\n");
-		log("        do not inser clock buffers, only simpe IO buffers\n");
+		log("        insert direct PAD->global_net buffers\n");
 		log("\n");
 		log("    -retime\n");
 		log("        run 'abc' with -dff option\n");
@@ -87,7 +87,7 @@ struct SynthSf2Pass : public ScriptPass
 		flatten = true;
 		retime = false;
 		iobs = true;
-		clkbuf = true;
+		clkbuf = false;
 	}
 
 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
@@ -134,8 +134,8 @@ struct SynthSf2Pass : public ScriptPass
 				iobs = false;
 				continue;
 			}
-			if (args[argidx] == "-noclkbuf") {
+			if (args[argidx] == "-clkbuf") {
-				clkbuf = false;
+				clkbuf = true;
 				continue;
 			}
 			break;
@@ -210,9 +210,9 @@ struct SynthSf2Pass : public ScriptPass
 		if (check_label("map_iobs"))
 		{
 			if (help_mode)
-				run("sf2_iobs [-noclkbuf]", "(unless -noiobs)");
+				run("sf2_iobs [-clkbuf]", "(unless -noiobs)");
 			else if (iobs)
-				run(clkbuf ? "sf2_iobs" : "sf2_iobs -noclkbuf");
+				run(clkbuf ? "sf2_iobs -clkbuf" : "sf2_iobs");
 			run("clean");
 		}