Various optimizations to LUT delay characterization

azonenberg · azonenberg · commit 5f4793935549 · 2017-06-04T19:41:32.000-07:00
diff --git a/src/gp4tchar/main.cpp b/src/gp4tchar/main.cpp
@@ -129,10 +129,10 @@ int main(int argc, char* argv[])
 		return 1;
 
 	//Measure delay through each element
-	//if(!MeasurePinToPinDelays(sock, hdev))
-	//	return 1;
-	//if(!MeasureCrossConnectionDelays(sock, hdev))
-	//	return 1;
+	if(!MeasurePinToPinDelays(sock, hdev))
+		return 1;
+	if(!MeasureCrossConnectionDelays(sock, hdev))
+		return 1;
 	if(!MeasureLUTDelays(sock, hdev))
 		return 1;
 
diff --git a/src/gp4tchar/measurements.cpp b/src/gp4tchar/measurements.cpp
@@ -62,7 +62,7 @@ bool MeasureLUTDelay(
 	int nlut,
 	int ninput,
 	PTVCorner corner,
-	float& delay);
+	map<PTVCorner, CombinatorialDelay>& delays);
 
 bool ProgramAndMeasureDelay(
 	Socket& sock,
@@ -73,6 +73,16 @@ bool ProgramAndMeasureDelay(
 	int voltage_mv,
 	float& delay);
 
+bool ProgramAndMeasureDelayAcrossVoltageCorners(
+	Socket& sock,
+	hdevice hdev,
+	vector<uint8_t>& bitstream,
+	int src,
+	int dst,
+	PTVCorner corner,
+	bool subtractPadDelay,
+	map<PTVCorner, CombinatorialDelay>& delays);
+
 float GetRoundTripDelayWith2x(
 	int src,
 	int dst,
@@ -273,6 +283,47 @@ bool ProgramAndMeasureDelay(
 	return MeasureDelay(sock, src, dst, delay);
 }
 
+bool ProgramAndMeasureDelayAcrossVoltageCorners(
+	Socket& sock,
+	hdevice hdev,
+	vector<uint8_t>& bitstream,
+	int src,
+	int dst,
+	PTVCorner corner,
+	bool subtractPadDelay,
+	map<PTVCorner, CombinatorialDelay>& delays)
+{
+	//Emulate the device
+	LogVerbose("Loading new bitstream\n");
+	if(!DownloadBitstream(hdev, bitstream, DownloadMode::EMULATION))
+		return false;
+
+	for(auto v : g_testVoltages)
+	{
+		corner.SetVoltage(v);
+		if(!PostProgramSetup(hdev, v))
+			return false;
+
+		//wait a bit to let voltages stabilize
+		usleep (1000 * 50);
+
+		float delay;
+		if(!MeasureDelay(sock, src, dst, delay))
+			return false;
+
+		//Remove off-die delays if requested
+		if(subtractPadDelay)
+		{
+			//Subtract PCB trace and IO buffer delays
+			delay -= GetRoundTripDelayWith2x(src, dst, corner);
+		}
+
+		delays[corner] = CombinatorialDelay(delay, -1);
+	}
+
+	return true;
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Characterize I/O buffers
 
@@ -588,28 +639,26 @@ bool MeasureLUTDelays(Socket& sock, hdevice hdev)
 
 	//Characterize each LUT
 	//Don't forget to only measure pins it actually has!
-	float delay;
 	for(unsigned int nlut = 0; nlut < g_calDevice.GetLUTCount(); nlut++)
 	{
 		auto baselut = g_calDevice.GetLUT(nlut);
 		auto lut = GetRealLUT(baselut);
-
-		//Try various voltages
-		for(auto voltage : g_testVoltages)
+		for(unsigned int npin = 0; npin < lut->GetOrder(); npin ++)
 		{
 			//Test conditions (TODO: pass this in from somewhere?)
-			PTVCorner corner(PTVCorner::SPEED_TYPICAL, 25, voltage);
-		
-			for(unsigned int npin = 0; npin < lut->GetOrder(); npin ++)
-			{
-				if(!MeasureLUTDelay(sock, hdev, nlut, npin, corner, delay))
-					return false;
+			PTVCorner corner(PTVCorner::SPEED_TYPICAL, 25, 3300);
+
+			map<PTVCorner, CombinatorialDelay> delays;
+			if(!MeasureLUTDelay(sock, hdev, nlut, npin, corner, delays))
+				return false;
 
-				//For now, the parent (in case of a muxed lut etc) stores all timing data
-				//TODO: does this make the most sense?
+			//For now, the parent (in case of a muxed lut etc) stores all timing data
+			//TODO: does this make the most sense?
+			for(auto it : delays)
+			{
 				char portname[] = "IN0";
 				portname[2] += npin;
-				baselut->AddCombinatorialDelay(portname, "OUT", corner, CombinatorialDelay(delay, -1));
+				baselut->AddCombinatorialDelay(portname, "OUT", it.first, it.second);
 			}
 		}
 	}
@@ -623,10 +672,8 @@ bool MeasureLUTDelay(
 	int nlut,
 	int ninput,
 	PTVCorner corner,
-	float& delay)
+	map<PTVCorner, CombinatorialDelay>& delays)
 {
-	delay = -1;
-
 	//Create the device object
 	Greenpak4Device device(part, unused_pull, unused_drive);
 	device.SetIOPrecharge(false);
@@ -675,12 +722,9 @@ bool MeasureLUTDelay(
 	device.WriteToBuffer(bitstream, 0, false);
 	//device.WriteToFile("/tmp/test.txt", 0, false);			//for debug in case of failure
 
-	//Get the delay
-	if(!ProgramAndMeasureDelay(sock, hdev, bitstream, src, dst, corner.GetVoltage(), delay))
+	//Get the delays
+	if(!ProgramAndMeasureDelayAcrossVoltageCorners(sock, hdev, bitstream, src, dst, corner, true, delays))
 		return false;
 
-	//Subtract PCB trace and IO buffer delays
-	delay -= GetRoundTripDelayWith2x(src, dst, corner);
-
 	return true;
 }
diff --git a/src/gp4tchar/setup.cpp b/src/gp4tchar/setup.cpp
@@ -25,6 +25,8 @@ using namespace std;
 
 bool PostProgramSetup(hdevice hdev, int voltage_mv)
 {
+	SetStatusLED(hdev, 1);
+
 	//Clear I/Os from programming mode
 	if(!IOReset(hdev))
 		return false;
diff --git a/src/xbpar/PTVCorner.h b/src/xbpar/PTVCorner.h
@@ -51,6 +51,10 @@ class PTVCorner
 	int GetVoltage() const
 	{ return m_voltage; }
 
+	//TODO: verify within legal limits
+	void SetVoltage(int v)
+	{ m_voltage = v; }
+
 	std::string toString() const;
 
 	//Comparison operator for STL collections

Original file line number	Diff line number	Diff line change
`@@ -25,6 +25,8 @@ using namespace std;`
`25`	`25`
`26`	`26`	`bool PostProgramSetup(hdevice hdev, int voltage_mv)`
`27`	`27`	`{`
	`28`	`+ SetStatusLED(hdev, 1);`
	`29`	`+`
`28`	`30`	`//Clear I/Os from programming mode`
`29`	`31`	`if(!IOReset(hdev))`
`30`	`32`	`return false;`