Remove unnecessary code

This commit is contained in:
Jan Käberich 2022-10-24 00:10:49 +02:00
parent 70488f8262
commit 5ee4208c32
2 changed files with 1 additions and 241 deletions

View File

@ -21,8 +21,6 @@ using namespace std::chrono_literals;
EyeDiagramPlot::EyeDiagramPlot(TraceModel &model, QWidget *parent)
: TracePlot(model, parent),
trace(nullptr),
updating(false),
updateScheduled(false),
xSamples(200),
datarate(100000000),
highlevel(1.0),
@ -88,9 +86,7 @@ void EyeDiagramPlot::enableTrace(Trace *t, bool enabled)
} else {
if(trace) {
tdr->removeInput();
while(updating) {
std::this_thread::sleep_for(20ms);
}
std::lock_guard<std::mutex> calc(calcMutex);
displayData->clear();
calcData->clear();
}
@ -724,238 +720,6 @@ QPointF EyeDiagramPlot::pixelToPlotValue(QPoint pixel)
return p;
}
void EyeDiagramPlot::updateThread(unsigned int xSamples)
{
std::lock_guard<std::mutex> calc(calcMutex);
do {
updateScheduled = false;
setStatus("Starting calculation...");
if(!trace) {
setStatus("No trace assigned");
continue;
}
qDebug() << "Starting eye diagram calculation";
// sanity check values
if(datarate >= trace->getSample(trace->numSamples() - 1).x) {
setStatus("Data rate too high");
continue;
}
if(datarate <= 0) {
setStatus("Data rate too low");
continue;
}
if(risetime > 0.3 * 1.0 / datarate) {
setStatus("Rise time too high");
continue;
}
if(falltime > 0.3 * 1.0 / datarate) {
setStatus("Fall time too high");
continue;
}
if(jitter > 0.3 * 1.0 / datarate) {
setStatus("Jitter too high");
continue;
}
qDebug() << "Eye calculation: input values okay";
// calculate timestep
double timestep = calculatedTime() / xSamples;
// reserve vector for input data
std::vector<std::complex<double>> inVec(xSamples * (cycles + 1), 0.0); // needs to calculate one more cycle than required for the display (settling)
// resize working buffer
qDebug() << "Clearing old eye data, calcData:" << calcData;
calcData->clear();
calcData->resize(xSamples);
for(auto& s : *calcData) {
s.y.resize(cycles, 0.0);
}
setStatus("Extracting impulse response...");
// calculate impulse response of trace
double eyeTimeShift = 0;
std::vector<std::complex<double>> impulseVec;
// determine how long the impulse response is
auto samples = tdr->numSamples();
if(samples == 0) {
// TDR calculation not yet done, unable to update
updating = false;
setStatus("No time-domain data from trace");
return;
}
auto length = tdr->getSample(samples - 1).x;
// determine average delay
auto total_step = tdr->getStepResponse(samples - 1);
for(unsigned int i=0;i<samples;i++) {
auto step = tdr->getStepResponse(i);
if(abs(total_step - step) <= abs(step)) {
// mid point reached
eyeTimeShift = tdr->getSample(i).x;
break;
}
}
unsigned long convolutedSize = length / timestep;
if(convolutedSize > inVec.size()) {
// impulse response is longer than what we display, truncate
convolutedSize = inVec.size();
}
impulseVec.resize(convolutedSize);
/*
* we can't use the impulse response directly because we most likely need samples inbetween
* the calculated values. Interpolation is available but if our sample spacing here is much
* wider than the impulse response data, we might miss peaks (or severely miscalculate their
* amplitude.
* Instead, the step response is interpolated and the impulse response determined by deriving
* it from the interpolated step response data. As the step response is the integrated imulse
* response data, we can't miss narrow peaks that way.
*/
double lastStepResponse = 0.0;
for(unsigned long i=0;i<convolutedSize;i++) {
auto x = i*timestep;
auto step = tdr->getInterpolatedStepResponse(x);
impulseVec[i] = step - lastStepResponse;
lastStepResponse = step;
}
eyeTimeShift += (risetime + falltime) * 1.25 / 4;
eyeTimeShift += 0.5 / datarate;
int eyeXshift = eyeTimeShift / timestep;
qDebug() << "Eye calculation: TDR calculation done";
setStatus("Generating PRBS sequence...");
auto prbs = PRBS(patternbits);
auto getNextLevel = [&]() -> unsigned int {
unsigned int level = 0;
for(unsigned int i=0;i<bitsPerSymbol;i++) {
level <<= 1;
if(prbs.next()) {
level |= 0x01;
}
}
return level;
};
auto levelToVoltage = [=](unsigned int level) -> double {
unsigned int maxLevel = (0x01 << bitsPerSymbol) - 1;
return Util::Scale((double) level, 0.0, (double) maxLevel, lowlevel, highlevel);
};
unsigned int currentSignal = getNextLevel();
unsigned int nextSignal = getNextLevel();
// initialize random generator
std::random_device rd1;
std::mt19937 mt_noise(rd1());
std::normal_distribution<> dist_noise(0, noise);
std::random_device rd2;
std::mt19937 mt_jitter(rd2());
std::normal_distribution<> dist_jitter(0, jitter);
unsigned int bitcnt = 1;
double transitionTime = -10; // assume that we start with a settled input, last transition was "long" ago
for(unsigned int i=0;i<inVec.size();i++) {
double time = (i+eyeXshift)*timestep;
double voltage = 0.0;
if(time >= transitionTime) {
// currently within a bit transition
double edgeTime = 0;
double expTimeConstant = 0.0;
if(currentSignal < nextSignal) {
edgeTime = risetime;
} else if(currentSignal > nextSignal) {
edgeTime = falltime;
}
if(linearEdge) {
// edge is modeled as linear rise/fall
// increase slightly to account for typical 10/90% fall/rise time
edgeTime *= 1.25;
} else {
// edge is modeled as exponential rise/fall. Adjust time constant to match
// selected rise/fall time (with 10-90% signal rise/fall within specified time)
expTimeConstant = edgeTime / 2.197224577;
edgeTime = 6 * expTimeConstant; // after six time constants, 99.7% of signal movement has happened
}
if(time >= transitionTime + edgeTime) {
// bit transition settled
voltage = levelToVoltage(nextSignal);
// move on to the next bit
currentSignal = nextSignal;
nextSignal = getNextLevel();
transitionTime = bitcnt * 1.0 / datarate + dist_jitter(mt_jitter);
bitcnt++;
} else {
// still within rise or fall time
double timeSinceEdge = time - transitionTime;
double from = levelToVoltage(currentSignal);
double to = levelToVoltage(nextSignal);
if(linearEdge) {
double edgeRatio = timeSinceEdge / edgeTime;
voltage = from * (1.0 - edgeRatio) + to * edgeRatio;
} else {
voltage = from + (1.0 - exp(-timeSinceEdge/expTimeConstant)) * (to - from);
}
}
} else {
// still before the next edge
voltage = levelToVoltage(currentSignal);
}
voltage += dist_noise(mt_noise);
inVec[i] = voltage;
}
// input voltage vector fully assembled
qDebug() << "Eye calculation: input data generated";
setStatus("Performing convolution...");
qDebug() << "Convolve via FFT start";
std::vector<std::complex<double>> outVec;
impulseVec.resize(inVec.size(), 0.0);
outVec.resize(inVec.size());
Fft::convolve(inVec, impulseVec, outVec);
qDebug() << "Convolve via FFT stop";
// fill data from outVec
for(unsigned int i=0;i<xSamples;i++) {
(*calcData).at(i).x = i * timestep;
}
for(unsigned int i=xSamples;i<inVec.size();i++) {
unsigned int x = i % xSamples;
unsigned int y = i / xSamples - 1;
(*calcData).at(x).y.at(y) = outVec[i].real();
}
qDebug() << "Eye calculation: Convolution done";
{
std::lock_guard<std::mutex> guard(bufferSwitchMutex);
// switch buffers
qDebug() << "Switching diplay buffers, calcData:" << calcData;
auto buf = displayData;
displayData = calcData;
calcData = buf;
if((*displayData)[0].y[0] == 0.0 && (*displayData)[0].y[1] == 0.0) {
qDebug() << "detected null after eye calculation";
}
qDebug() << "Buffer switch complete, displayData:" << displayData;
}
setStatus("Eye calculation complete");
replot();
} while (updateScheduled);
updating = false;
}
void EyeDiagramPlot::triggerUpdate()
{
// trigger the thread
@ -1051,7 +815,6 @@ void EyeThread::run()
auto samples = eye.tdr->numSamples();
if(samples == 0) {
// TDR calculation not yet done, unable to update
eye.updating = false;
eye.setStatus("No time-domain data from trace");
continue;
}

View File

@ -69,7 +69,6 @@ private:
static constexpr double yOverrange = 0.2;
QPoint plotValueToPixel(QPointF plotValue);
QPointF pixelToPlotValue(QPoint pixel);
void updateThread(unsigned int xSamples);
void setStatus(QString s);
double calculatedTime();
double minDisplayVoltage();
@ -91,8 +90,6 @@ private:
std::vector<Xdata> data[2];
std::vector<Xdata> *displayData;
std::vector<Xdata> *calcData;
bool updating;
bool updateScheduled;
unsigned int xSamples;
double datarate;