select_initiator.cpp

SystemC Transaction Level Modelling. 是基于SystemC之上的总线互联协议

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//=============================================================================
///  @file select_initiator.cpp
///  @Details Implements a AT non blocking initiator 
//
//=============================================================================
//  Original Authors:
//    Bill Bunton, ESLX
//    Charles Wilson, ESLX
//    Anna Keist, ESLX
//=============================================================================

#include "reporting.h"                                // Reporting convenience macros
#include "select_initiator.h"                         // Our header
#include "tlm.h"                                      // TLM headers

using namespace sc_core;

static const char *filename = "select_initiator.cpp";  ///  filename for reporting

//=============================================================================
///Constructor

select_initiator::select_initiator                  // constructor
( sc_module_name name                               // module name
, const unsigned int ID                             // initiator ID
, sc_core::sc_time end_rsp_delay                    // delay
)
: sc_module           (name)                        /// init module name
, initiator_socket    ("initiator_socket")          /// init socket name

, m_send_end_rsp_PEQ  ("send_end_rsp_PEQ")          /// init PEQ name  
, m_ID            (ID)                              /// init initiator ID
, m_end_rsp_delay (end_rsp_delay)                   /// init end response delay

{ 
 m_enable_target_tracking = true;   /// init style tracking mode????


  // bind initiator to the export
  initiator_socket (*this);                     

  // register thread process
  SC_THREAD(initiator_thread);                  

  // register method process
  SC_METHOD(send_end_rsp_method)              
    sensitive << m_send_end_rsp_PEQ.get_event();
    dont_initialize();  
}

//=============================================================================
//
//  Initiator thread
//
//=============================================================================
void select_initiator::initiator_thread(void)   // initiator thread
{  
  tlm::tlm_generic_payload *transaction_ptr;    // transaction pointer
  std::ostringstream       msg;                 // log message

  while (true) 
  {
//=============================================================================
// Read FIFO to Get new transaction GP from the traffic generator 
//=============================================================================
    transaction_ptr = request_in_port->read();  // get request from input fifo
  
    tlm::tlm_phase phase  = tlm::BEGIN_REQ;     // Create phase objects 
    sc_time delay         = SC_ZERO_TIME;       // Create delay objects 

    std::ostringstream  msg;                    // log message
    
    msg.str("");
    msg << "Initiator: " << m_ID 
        << " starting new transaction" 
        << endl << "      " 
        << "Initiator: " << m_ID               
        << " nb_transport_fw (GP, " 
        << report::print(phase) << ", "
        << delay << ")";
    REPORT_INFO(filename,  __FUNCTION__, msg.str());

//-----------------------------------------------------------------------------
// Make the non-blocking call and decode returned status (tlm_sync_enum) 
//-----------------------------------------------------------------------------
    tlm::tlm_sync_enum 
    return_value = initiator_socket->nb_transport_fw(*transaction_ptr, phase, delay);
    
    msg.str("");
    msg << "Initiator: " << m_ID
      << " " << report::print(return_value) <<  " (GP, "
      << report::print(phase) << ", "
      << delay << ")" << endl; 

    switch (return_value) 
    {
//-----------------------------------------------------------------------------
//  The target returned COMPLETED this is a single phase transaction 
//    Wait the annotated delay
//    Return the transaction to the traffic generator 
//-----------------------------------------------------------------------------
      case tlm::TLM_COMPLETED: 
      {
        wait(delay + m_end_rsp_delay);              // wait the annotated delay 

        msg << "      "
          << "Initiator: " << m_ID
          << " target returned COMPLETED with annotated time ";
        REPORT_INFO (filename, __FUNCTION__, msg.str() );

        response_out_port->write(transaction_ptr);  // return txn to traffic gen

        break;
      }// end case TLM_COMPLETED

//-----------------------------------------------------------------------------
// Target returned UPDATED this will be 2 phase transaction 
//    Add the transaction pointer to the waiting backward path map  
//    Set tracking enum to Rcved_UPDATED 
//    Wait the annotated delay
//-----------------------------------------------------------------------------
      case tlm::TLM_UPDATED: 
      {
        if( phase == tlm::END_REQ) {

          if (m_enable_target_tracking) {
            m_waiting_bw_path_map.insert(make_pair(transaction_ptr
                                                  ,Rcved_UPDATED_enum
                                                  ));          
          }
          else {
            m_waiting_bw_path_map.insert(make_pair(transaction_ptr
                                                  ,Rcved_END_REQ_enum
                                                  )); 
          }
            wait(delay);                    // wait the annotated delay 
            
            msg << "      "
              << "Initiator: " << m_ID
              << " transaction waiting begin-response on backward path"; 
            REPORT_INFO (filename, __FUNCTION__, msg.str() );

        }
        else if( phase == tlm::BEGIN_RESP) {
        // ?????
        }

        else {
          msg << "      "
          << "Initiator: " << m_ID
          << " Unexpected phase for UPDATED return from target ";
          REPORT_FATAL (filename, __FUNCTION__, msg.str() );
        }
        break;
      } // end case TLM_UPDATED


//-----------------------------------------------------------------------------
//  Target returned ACCEPTED this will be 4 phase transaction 
//    Add the transaction pointer to the waiting backward path map  
//    Set tracking enum to Rcved_END_REQ 
//    When the END REQUEST RULE is active wait for the target to response
//-----------------------------------------------------------------------------
      case tlm::TLM_ACCEPTED:
      {
        msg << "      "
        << "Initiator: " << m_ID 
        << " transaction waiting end-request on backward-path ";
        REPORT_INFO (filename, __FUNCTION__, msg.str() );
        
        //  use map to track transaction including current state information 
        m_waiting_bw_path_map.insert (make_pair (transaction_ptr
                                                ,Rcved_ACCEPTED_enum
                                                ));  
                                                
        wait (m_enable_next_request_event);                                     
      
        break;
        
      } // end case TLM_ACCEPTED


//-----------------------------------------------------------------------------
// All case covered default 
//-----------------------------------------------------------------------------
      default:
      {
        msg << "      "
        << "Initiator: " << m_ID 
        << " Unexpected response to BEGIN_REQ ";
        REPORT_FATAL (filename, __FUNCTION__, msg.str() );
        break;
      }
    } // end case
  } // end while true
} // end initiator_thread 



//=============================================================================
///  @fn select_initiator::nb_transport_bw
//
///  @brief non-blocking transport from targets
//
//=============================================================================
tlm::tlm_sync_enum    
select_initiator::nb_transport_bw                       // inbound nb_transport_bw
( tlm::tlm_generic_payload&  transaction_ref            // generic payload
 , tlm::tlm_phase&            phase                     // tlm phase
 , sc_time&                   delay                     // delay
 )

{
  tlm::tlm_sync_enum        status = tlm::TLM_COMPLETED;  // return status reject by default
  std::ostringstream        msg;                          // log message
  
//=============================================================================
// Check waiting backward path map of valid transaction  
//=============================================================================
  waiting_bw_path_map::iterator transaction_pair ;        // create interator for map

  transaction_pair  = m_waiting_bw_path_map.find(&transaction_ref); 
  
  if (transaction_pair == m_waiting_bw_path_map.end() ) {   
            
//=============================================================================
//  The transaction pointer used by the backward path call does not belong 
//  to this initiator, this is a major error 
//=============================================================================
    msg << "      "
    << "Initiator: " << m_ID 
    << " Received invalid transaction pointer";
    REPORT_FATAL (filename, __FUNCTION__, msg.str() );
  }

//=============================================================================
//  Normal operation  
//    Decode backward path phase