SAC.h

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// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
// All rights not expressly granted are reserved.
//
// This software is distributed under the terms of the GNU General Public
// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
//
// In applying this license CERN does not waive the privileges and immunities
// granted to it by virtue of its status as an Intergovernmental Organization
// or submit itself to any jurisdiction.
 
 
#ifndef ALICEO2_DATAFORMATSTPC_SAC_H
#define ALICEO2_DATAFORMATSTPC_SAC_H
 
#include <cstdint>
#include <string_view>
 
namespace o2::tpc::sac
{
 
static constexpr uint32_t FEsPerInstance = 9;
 
struct headerDef {
  static constexpr uint32_t MagicWord = 0xabcd; 
 
  union {
    uint64_t word0 = 0;            
    struct {                       
      uint32_t version : 8;        
      uint32_t instance : 4;       
      uint32_t empty0 : 8;         
      uint32_t bunchCrossing : 12; 
      uint32_t orbit : 32;         
    };                             
  };                               
  union {                          
    uint64_t word1 = 0;            
    struct {                       
      uint32_t pktCount : 16;      
      uint32_t empty1_0 : 16;      
      uint32_t empty1_1;           
    };                             
  };                               
  union {                          
    uint64_t word2 = 0;            
  };                               
  union {                          
    uint64_t word3 = 0;            
    struct {                       
      uint32_t empty3_0;           
      uint32_t empty3_1 : 16;      
      uint32_t magicWord : 16;     
    };                             
  };                               
 
  bool check() const { return magicWord == MagicWord; }
};
 
struct dataDef {
  static constexpr uint32_t HeaderWord = 0xdeadbeef;
  static constexpr uint32_t TrailerWord = 0xbeefdead;
  static constexpr uint32_t PacketSize = 1024;
  static constexpr uint32_t DataSize = 1000;
 
  uint32_t header = 0;       
  union {                    
    uint32_t sizeFE = 0;     
    struct {                 
      uint32_t feid : 8;     
      uint32_t pktSize : 24; 
    };                       
  };                         
  uint32_t pktNumber = 0;    
  uint32_t timeStamp = 0;    
  char dataWords[DataSize];  
  uint32_t crc32 = 0;        
  uint32_t trailer = 0;      
 
  bool check() const
  {
    return (header == HeaderWord) && (trailer == TrailerWord) && (pktSize == PacketSize);
  }
};
 
struct packet {
  headerDef header;
  dataDef data;
 
  uint32_t getInstance() const
  {
    return header.instance;
  }
 
  uint32_t getFEIndex() const
  {
    return data.feid - 1 + header.instance * FEsPerInstance;
  }
 
  std::string_view getDataWords()
  {
    return std::string_view(data.dataWords, dataDef::DataSize);
  }
 
  bool check() const
  {
    return header.check() && data.check();
  }
 
  int getCheckMask() const
  {
    return (header.check() << 1) | data.check();
  }
};
 
} // namespace o2::tpc::sac
 
#endif