#include <HcalTDC.h>

Public Member Functions
unsigned int	getThresholdDAC ()

	HcalTDC (unsigned int thresholdDAC=12)

void	setDbService (const HcalDbService *service)
	the Producer will probably update this every event More...

void	setThresholdDAC (unsigned int DAC)

template<class Digi >
void	timing (const CaloSamples &lf, Digi &digi, CLHEP::HepRandomEngine *) const
	adds timing information to the digi More...

	~HcalTDC ()

Private Member Functions
double	getHysteresisThreshold (double nominal) const

double	getThreshold (const HcalGenericDetId &detId, CLHEP::HepRandomEngine *) const

Private Attributes
double const	lsb

unsigned int	theDAC

const HcalDbService *	theDbService

HcalTDCParameters	theTDCParameters

Detailed Description

Definition at line 15 of file HcalTDC.h.

Constructor & Destructor Documentation

HcalTDC::HcalTDC ( unsigned int thresholdDAC = 12 )

Definition at line 8 of file HcalTDC.cc.

                                           : theTDCParameters(), 
                           theDbService(0),
                           theDAC(thresholdDAC),
                           lsb(3.74) {}

HcalTDC::~HcalTDC ( )

Definition at line 13 of file HcalTDC.cc.

13 {

14 }

Member Function Documentation

double HcalTDC::getHysteresisThreshold ( double nominal ) const

private

Definition at line 124 of file HcalTDC.cc.

References lsb.

                                                            {
   // the TDC will "re-arm" when it crosses the threshold minus 2.5 mV.
   // the lsb is 44kOhm * (3.74 uA / 24) = 6.86 mV.  2.5 mV is 0.36 lsb.
   // with the this means that the hysteresis it isn't far from the nominal 
   // threshold
 
   return nominal - 0.365*lsb;
 }

double HcalTDC::getThreshold	(	const HcalGenericDetId &	detId,
		CLHEP::HepRandomEngine *	engine
	)		const

private

Definition at line 109 of file HcalTDC.cc.

References HcalTDCParameters::deltaT(), HcalDbService::getHcalCalibrations(), HcalDbService::getHcalCalibrationWidths(), lsb, HcalTDCParameters::nbins(), muonCSCDigis_cfi::pedestal, HcalCalibrationWidths::pedestal(), HcalCalibrations::pedestal(), theDAC, theDbService, and theTDCParameters.

Referenced by timing().

                                                                                                {
   // subtract off pedestal and noise once
   double pedestal = theDbService->getHcalCalibrations(detId).pedestal(0);
   double pedestalWidth = theDbService->getHcalCalibrationWidths(detId).pedestal(0);
   // here the TDCthreshold_ is a multiple of the least significant bit 
   // for the TDC portion of the QIE.  The nominal reference is 40 uA which is
   // divided by an 8 bit DAC.  This means the least significant bit is 0.135 uA
   // in the TDC circuit or 3.74 uA at the input current.
 
   // the pedestal is assumed to be evenly distributed in time with some
   // random variation.
 
   return lsb*theDAC - CLHEP::RandGaussQ::shoot(engine, pedestal,  pedestalWidth)/theTDCParameters.deltaT()/theTDCParameters.nbins();
 }

unsigned int HcalTDC::getThresholdDAC ( )

inline

Definition at line 29 of file HcalTDC.h.

29 { return theDAC; }

HcalTDC::theDAC

unsigned int theDAC

Definition: HcalTDC.h:38

void HcalTDC::setDbService ( const HcalDbService * service )

the Producer will probably update this every event

Definition at line 133 of file HcalTDC.cc.

References theDbService.

Referenced by HcalElectronicsSim::setDbService().

                                                         {
   theDbService = service;
 }

void HcalTDC::setThresholdDAC ( unsigned int DAC )

inline

Definition at line 28 of file HcalTDC.h.

28 { theDAC = DAC; }

HcalTDC::theDAC

unsigned int theDAC

Definition: HcalTDC.h:38

template<class Digi >

void HcalTDC::timing	(	const CaloSamples &	lf,
		Digi &	digi,
		CLHEP::HepRandomEngine *	engine
	)		const

adds timing information to the digi

Definition at line 17 of file HcalTDC.cc.

References HcalTDCParameters::alreadyTransitionCode(), getThreshold(), i, HcalTDCParameters::nbins(), HcalTDCParameters::noTransitionCode(), CaloSamples::preciseAt(), CaloSamples::preciseSize(), CaloSamples::size(), and theTDCParameters.

                                                                                           {
 
   float const TDC_Threshold(getThreshold(digi.id(), engine));
   float const TDC_Threshold_hyst(TDC_Threshold);
   bool risingReady(true), fallingReady(false);
   int tdcBins = theTDCParameters.nbins();
   // start with a loop over 10 samples
   bool hasTDCValues=true;
   if (lf.preciseSize()==0 ) hasTDCValues=false;
 
   // "AC" hysteresis from Tom:  There cannot be a second transition
   // within the QIE within 3ns
   int const rising_ac_hysteresis(5);
   int lastRisingEdge(0);
 
   // if (hasTDCValues)
   //   std::cout << digi.id() 
   //          << " threshold: " << TDC_Threshold
   //          << '\n';
   for (int ibin = 0; ibin < lf.size(); ++ibin) {
     /*
     If in a given 25ns bunch/time sample, the pulse is above
     TDC_Thresh already, then TDC_RisingEdge=0 if it was low in the
     last precision bin on the previous bunch crossing, otherwise,
     TDC_RisingEdge=63 if the pulse never crosses the threshold
     having started off, then the special code is 62 and then
     one can still have a TDC_FallingEdge that is valid.  If the pulse
     never falls below threshold having started above threshold (or
     goes above threshold in the bunch crossing and doesn't come down),
     then TDC_FallingEdge=.  If the pulse never went above
     threshold, then TDC_RisingEdge=63 and
     TDC_FallingEdge=62.
     */
     // special codes
     int TDC_RisingEdge = (risingReady) ? 
       theTDCParameters.noTransitionCode() :
       theTDCParameters.alreadyTransitionCode();
     int TDC_FallingEdge = (fallingReady) ? 
       theTDCParameters.alreadyTransitionCode() :
       theTDCParameters.noTransitionCode();
     int preciseBegin = ibin * tdcBins;
     int preciseEnd = preciseBegin + tdcBins;
     if ( hasTDCValues) {
       // std::cout << " alreadyOn: " << alreadyOn << '\n';
       for(int i = preciseBegin; i < preciseEnd; ++i) { 
       //    std::cout << " preciseBin: " << i
       //                << " preciseAt(i): " << lf.preciseAt(i);
     if( (fallingReady) && (i%3 == 0) && (lf.preciseAt(i) < TDC_Threshold)) {
       fallingReady = false;
       TDC_FallingEdge = i-preciseBegin;
       // std::cout << " falling ";
     }
     if ((risingReady) && (lf.preciseAt(i) > TDC_Threshold)) {
       risingReady = false;
       TDC_RisingEdge = i-preciseBegin;
       lastRisingEdge = 0;
       // std::cout << " rising ";
     }
     // std::cout << '\n';
 
     //This is the place for hysteresis code.  Need to to arm the
     //tdc by setting the risingReady or fallingReady to true.
 
     if ((!fallingReady) && (lf.preciseAt(i) > TDC_Threshold)) {
       fallingReady = true;
       if (TDC_FallingEdge == theTDCParameters.alreadyTransitionCode())
         TDC_FallingEdge = theTDCParameters.noTransitionCode();
     }
     if ((!risingReady) && (lastRisingEdge > rising_ac_hysteresis) &&
         (lf.preciseAt(i) < TDC_Threshold_hyst)) {
       risingReady = true;
       if (TDC_RisingEdge == theTDCParameters.alreadyTransitionCode())
         TDC_RisingEdge = theTDCParameters.noTransitionCode();
     }
     ++lastRisingEdge;
       }
     }
     // change packing to allow for special codes
     int packedTDC = TDC_RisingEdge + (tdcBins*2) * TDC_FallingEdge;
     digi.setSample(ibin, digi.adc(ibin), packedTDC, true);
     // if ( hasTDCValues) {
     //   std::cout << " sample: " << ibin 
     //      << " adc: " << digi.adc(ibin)
     //      << " fC: " << digi[ibin].nominal_fC()
     //      << " risingEdge: " << TDC_RisingEdge
     //      << " fallingEdge: " << TDC_FallingEdge
     //      << " packedTDC: " << packedTDC
     //      << std::endl;
     // }
   } // loop over bunch crossing bins
 }