1 files changed, 58 insertions, 6 deletions

diff --git a/techlibs/coolrunner2/coolrunner2_sop.cc b/techlibs/coolrunner2/coolrunner2_sop.cc
index b57214ccb..de0cbb29d 100644
--- a/techlibs/coolrunner2/coolrunner2_sop.cc
+++ b/techlibs/coolrunner2/coolrunner2_sop.cc
@@ -25,7 +25,7 @@ PRIVATE_NAMESPACE_BEGIN
 
 struct Coolrunner2SopPass : public Pass {
 	Coolrunner2SopPass() : Pass("coolrunner2_sop", "break $sop cells into ANDTERM/ORTERM cells") { }
-	virtual void help()
+	void help() YS_OVERRIDE
 	{
 		log("\n");
 		log("    coolrunner2_sop [options] [selection]\n");
@@ -33,7 +33,7 @@ struct Coolrunner2SopPass : public Pass {
 		log("Break $sop cells into ANDTERM/ORTERM cells.\n");
 		log("\n");
 	}
-	virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
 	{
 		log_header(design, "Executing COOLRUNNER2_SOP pass (break $sop cells into ANDTERM/ORTERM cells).\n");
 		extra_args(args, 1, design);
@@ -60,10 +60,8 @@ struct Coolrunner2SopPass : public Pass {
 			dict<SigBit, pool<tuple<Cell*, std::string>>> special_pterms_inv;
 			for (auto cell : module->selected_cells())
 			{
-				if (cell->type == "\\FDCP" || cell->type == "\\FDCP_N" || cell->type == "\\FDDCP" ||
-					cell->type == "\\FTCP" || cell->type == "\\FTCP_N" || cell->type == "\\FTDCP" ||
-					cell->type == "\\FDCPE" || cell->type == "\\FDCPE_N" || cell->type == "\\FDDCPE" ||
-					cell->type == "\\LDCP" || cell->type == "\\LDCP_N")
+				if (cell->type.in("\\FDCP", "\\FDCP_N", "\\FDDCP", "\\FTCP", "\\FTCP_N", "\\FTDCP",
+							"\\FDCPE", "\\FDCPE_N", "\\FDDCPE", "\\LDCP", "\\LDCP_N"))
 				{
 					if (cell->hasPort("\\PRE"))
 						special_pterms_no_inv[sigmap(cell->getPort("\\PRE")[0])].insert(
@@ -250,6 +248,60 @@ struct Coolrunner2SopPass : public Pass {
 				}
 			}
 
+			// In some cases we can get a FF feeding straight into an FF. This is not possible, so we need to insert
+			// some AND/XOR cells in the middle to make it actually work.
+
+			// Find all the FF outputs
+			pool<SigBit> sig_fed_by_ff;
+			for (auto cell : module->selected_cells())
+			{
+				if (cell->type.in("\\FDCP", "\\FDCP_N", "\\FDDCP", "\\LDCP", "\\LDCP_N",
+							"\\FTCP", "\\FTCP_N", "\\FTDCP", "\\FDCPE", "\\FDCPE_N", "\\FDDCPE"))
+				{
+					auto output = sigmap(cell->getPort("\\Q")[0]);
+					sig_fed_by_ff.insert(output);
+				}
+			}
+
+			// Look at all the FF inputs
+			for (auto cell : module->selected_cells())
+			{
+				if (cell->type.in("\\FDCP", "\\FDCP_N", "\\FDDCP", "\\LDCP", "\\LDCP_N",
+							"\\FTCP", "\\FTCP_N", "\\FTDCP", "\\FDCPE", "\\FDCPE_N", "\\FDDCPE"))
+				{
+					SigBit input;
+					if (cell->type.in("\\FTCP", "\\FTCP_N", "\\FTDCP"))
+						input = sigmap(cell->getPort("\\T")[0]);
+					else
+						input = sigmap(cell->getPort("\\D")[0]);
+
+					if (sig_fed_by_ff[input])
+					{
+						printf("Buffering input to \"%s\"\n", cell->name.c_str());
+
+						auto and_to_xor_wire = module->addWire(NEW_ID);
+						auto xor_to_ff_wire = module->addWire(NEW_ID);
+
+						auto and_cell = module->addCell(NEW_ID, "\\ANDTERM");
+						and_cell->setParam("\\TRUE_INP", 1);
+						and_cell->setParam("\\COMP_INP", 0);
+						and_cell->setPort("\\OUT", and_to_xor_wire);
+						and_cell->setPort("\\IN", input);
+						and_cell->setPort("\\IN_B", SigSpec());
+
+						auto xor_cell = module->addCell(NEW_ID, "\\MACROCELL_XOR");
+						xor_cell->setParam("\\INVERT_OUT", false);
+						xor_cell->setPort("\\IN_PTC", and_to_xor_wire);
+						xor_cell->setPort("\\OUT", xor_to_ff_wire);
+
+						if (cell->type.in("\\FTCP", "\\FTCP_N", "\\FTDCP"))
+							cell->setPort("\\T", xor_to_ff_wire);
+						else
+							cell->setPort("\\D", xor_to_ff_wire);
+					}
+				}
+			}
+
 			// Actually do the removal now that we aren't iterating
 			for (auto cell : cells_to_remove)
 			{