DTConfigLUTs.cc

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//-------------------------------------------------
//
//   Class: DTConfigLUTs
//
//   Description: Configurable parameters and constants
//   for Level1 Mu DT Trigger - LUTs
//
//
//   Author List:
//   S. Vanini
//
//-----------------------------------------------------------------------

//-----------------------
// This Class's Header --
//-----------------------
#include "L1TriggerConfig/DTTPGConfig/interface/DTConfigLUTs.h"

//---------------
// C++ Headers --
//---------------
#include <cmath>
#include <cstring>

//-------------------------------
// Collaborating Class Headers --
//-------------------------------

#include "FWCore/Utilities/interface/Exception.h"

//----------------
// Constructors --
//----------------
DTConfigLUTs::DTConfigLUTs(const edm::ParameterSet& ps) { setDefaults(ps); }

DTConfigLUTs::DTConfigLUTs(bool debugLUTS, unsigned short int* buffer) {
  m_debug = debugLUTS;

  // check if this is a LUT configuration string
  if (buffer[2] != 0xA8) {
    throw cms::Exception("DTTPG") << "===> ConfigLUTs constructor : not a LUT string!" << std::endl;
  }

  // decode
  short int memory_lut[7];
  int c = 3;
  for (int i = 0; i < 7; i++) {
    memory_lut[i] = (buffer[c] << 8) | buffer[c + 1];
    c += 2;
    //std::cout << hex << memory_bti[i] << "  ";
  }

  // decode
  int btic = memory_lut[0];
  float d;
  DSPtoIEEE32(memory_lut[1], memory_lut[2], &d);
  float Xcn;
  DSPtoIEEE32(memory_lut[3], memory_lut[4], &Xcn);
  int wheel = memory_lut[5];

  // set parameters
  setBTIC(btic);
  setD(d);
  setXCN(Xcn);
  setWHEEL(wheel);

  return;
}

//--------------
// Destructor --
//--------------
DTConfigLUTs::~DTConfigLUTs() {}

//--------------
// Operations --
//--------------

void DTConfigLUTs::setDefaults(const edm::ParameterSet& m_ps) {
  // Debug flag
  m_debug = m_ps.getUntrackedParameter<bool>("Debug");

  // BTIC parameter
  m_btic = m_ps.getUntrackedParameter<int>("BTIC");

  // d: distance vertex to normal, unit cm.
  m_d = m_ps.getUntrackedParameter<double>("D");

  // Xcn: distance vertex to normal, unit cm.
  m_Xcn = m_ps.getUntrackedParameter<double>("XCN");

  // wheel sign (-1 or +1)
  m_wheel = m_ps.getUntrackedParameter<int>("WHEEL");
}

void DTConfigLUTs::print() const {
  std::cout << "******************************************************************************" << std::endl;
  std::cout << "*              DTTrigger configuration : LUT parameters             *" << std::endl;
  std::cout << "******************************************************************************" << std::endl
            << std::endl;
  std::cout << "Debug flag : " << debug() << std::endl;
  std::cout << "BTIC parameter : " << m_btic << std::endl;
  std::cout << "d: distance vertex to normal, unit cm. " << m_d << std::endl;
  std::cout << "Xcn: distance vertex to normal, unit cm. " << m_Xcn << std::endl;
  std::cout << "wheel sign " << m_wheel << std::endl;
  std::cout << "******************************************************************************" << std::endl;
}

void DTConfigLUTs::DSPtoIEEE32(short DSPmantissa, short DSPexp, float* f) const {
  DSPexp -= 15;
  *f = DSPmantissa * (float)pow(2.0, DSPexp);
  return;
}

void DTConfigLUTs::IEEE32toDSP(float f, short int& DSPmantissa, short int& DSPexp) const {
  long int pl = 0;
  static_assert(sizeof(decltype(pl)) >= sizeof(float));

  DSPmantissa = 0;
  DSPexp = 0;

  if (f != 0.0) {
    //pl = (long *)&f;
    memcpy(&pl, &f, sizeof(float));
    bool sign = false;
    if ((pl & 0x80000000) != 0)
      sign = true;
    long int lm = (0x800000 | (pl & 0x7FFFFF));  // [1][23bit mantissa]
    lm >>= 9;                                    //reduce to 15bits
    lm &= 0x7FFF;
    DSPexp = ((pl >> 23) & 0xFF) - 126;
    DSPmantissa = (short)lm;
    if (sign)
      DSPmantissa = -DSPmantissa;  // convert negative value in 2.s complement
  }
  return;
}