Timing analyzer is now aware of which cells are stateful, and won't report false combinatorial loops for stateful logic. No timing data for these blocks yet, though.

azonenberg · azonenberg · commit 1d910aabf889 · 2017-06-24T15:33:02.000-07:00
diff --git a/src/gp4par/par_reporting.cpp b/src/gp4par/par_reporting.cpp
@@ -264,8 +264,7 @@ void PrintTimingReport(Greenpak4Netlist* netlist, Greenpak4Device* device)
 	{
 		auto cell = it->second;
 
-		//TODO: check stateful internal blocks too
-		if(!cell->IsIbuf())
+		if(!cell->IsIbuf() && !cell->IsStateful())
 			continue;
 		sources.emplace(cell);
 	}
@@ -278,7 +277,7 @@ void PrintTimingReport(Greenpak4Netlist* netlist, Greenpak4Device* device)
 		auto cell = it->second;
 
 		//TODO: check stateful internal blocks too
-		if(!cell->IsObuf())
+		if(!cell->IsObuf() && !cell->IsStateful())
 			continue;
 		sinks.emplace(cell);
 	}
diff --git a/src/greenpak4/Greenpak4NetlistCell.cpp b/src/greenpak4/Greenpak4NetlistCell.cpp
@@ -29,6 +29,9 @@ Greenpak4NetlistCell::~Greenpak4NetlistCell()
 	//do not delete wires, module dtor handles that
 }
 
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Accessors
+
 string Greenpak4NetlistCell::GetLOC()
 {
 	string loc = m_attributes.at("LOC");
@@ -98,3 +101,21 @@ string Greenpak4NetlistCell::GetLOC()
 	else
 		return loc;
 }
+
+bool Greenpak4NetlistCell::IsStateful()
+{
+	if(m_type.find("GP_COUNT") == 0)
+		return true;
+	if(m_type.find("GP_DFF") == 0)
+		return true;
+	if(m_type.find("GP_DLATCH") == 0)
+		return true;
+	if(m_type == "GP_PGEN")
+		return true;
+	if(m_type.find("GP_SHREG") == 0)
+		return true;
+	if(m_type.find("GP_SPI") == 0)
+		return true;
+
+	return false;
+}
diff --git a/src/greenpak4/Greenpak4NetlistCell.h b/src/greenpak4/Greenpak4NetlistCell.h
@@ -66,6 +66,9 @@ class Greenpak4NetlistCell : public Greenpak4NetlistEntity
 	bool IsPowerRail()
 	{ return (m_type == "GP_VDD") || (m_type == "GP_VSS"); }
 
+	//Indicates whether the cell is stateful (can start or end a combinatorial path)
+	bool IsStateful();
+
 	std::string GetLOC();
 
 	bool HasLOC()

Original file line number	Diff line number	Diff line change
`@@ -264,8 +264,7 @@ void PrintTimingReport(Greenpak4Netlist* netlist, Greenpak4Device* device)`
`264`	`264`	`{`
`265`	`265`	`auto cell = it->second;`
`266`	`266`
`267`		`- //TODO: check stateful internal blocks too`
`268`		`- if(!cell->IsIbuf())`
	`267`	`+ if(!cell->IsIbuf() && !cell->IsStateful())`
`269`	`268`	`continue;`
`270`	`269`	`sources.emplace(cell);`
`271`	`270`	`}`
`@@ -278,7 +277,7 @@ void PrintTimingReport(Greenpak4Netlist* netlist, Greenpak4Device* device)`
`278`	`277`	`auto cell = it->second;`
`279`	`278`
`280`	`279`	`//TODO: check stateful internal blocks too`
`281`		`- if(!cell->IsObuf())`
	`280`	`+ if(!cell->IsObuf() && !cell->IsStateful())`
`282`	`281`	`continue;`
`283`	`282`	`sinks.emplace(cell);`
`284`	`283`	`}`