src/systemc/tests/include/SimpleATTarget1.h

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#ifndef __SIMPLE_AT_TARGET1_H__
#define __SIMPLE_AT_TARGET1_H__

#include "tlm.h"
#include "tlm_utils/simple_target_socket.h"
//#include <systemc>
#include <cassert>
#include <vector>
#include <queue>
//#include <iostream>

class SimpleATTarget1 : public sc_core::sc_module
{
public:
  typedef tlm::tlm_generic_payload            transaction_type;
  typedef tlm::tlm_phase                      phase_type;
  typedef tlm::tlm_sync_enum                  sync_enum_type;
  typedef tlm_utils::simple_target_socket<SimpleATTarget1> target_socket_type;

public:
  target_socket_type socket;

public:
  SC_HAS_PROCESS(SimpleATTarget1);
  SimpleATTarget1(sc_core::sc_module_name name) :
    sc_core::sc_module(name),
    socket("socket"),
    ACCEPT_DELAY(25, sc_core::SC_NS),
    RESPONSE_DELAY(100, sc_core::SC_NS)
  {
    // register nb_transport method
    socket.register_nb_transport_fw(this, &SimpleATTarget1::myNBTransport);

    SC_METHOD(endRequest)
    sensitive << mEndRequestEvent;
    dont_initialize();

    SC_METHOD(beginResponse)
    sensitive << mBeginResponseEvent;
    dont_initialize();

    SC_METHOD(endResponse)
    sensitive << mEndResponseEvent;
    dont_initialize();
  }

  //
  // Simple AT target
  // - Request is accepted after ACCEPT delay (relative to end of prev request
  //   phase)
  // - Response is started after RESPONSE delay (relative to end of prev resp
  //   phase)
  //
  sync_enum_type myNBTransport(transaction_type& trans, phase_type& phase, sc_core::sc_time& t)
  {
    if (phase == tlm::BEGIN_REQ) {
      // transactions may be kept in queue after the initiator has send END_REQ
      trans.acquire();

      sc_dt::uint64 address = trans.get_address();
      assert(address < 400);

      unsigned int& data = *reinterpret_cast<unsigned int*>(trans.get_data_ptr());
      if (trans.get_command() == tlm::TLM_WRITE_COMMAND) {
        std::cout << name() << ": Received write request: A = 0x"
                  << std::hex << (unsigned int)address << ", D = 0x"
                  << data << std::dec
                  << " @ " << sc_core::sc_time_stamp() << std::endl;

        *reinterpret_cast<unsigned int*>(&mMem[address]) = data;

      } else {
        std::cout << name() << ": Received read request: A = 0x"
                  << std::hex << (unsigned int)address << std::dec
                  << " @ " << sc_core::sc_time_stamp() << std::endl;

        data = *reinterpret_cast<unsigned int*>(&mMem[address]);
      }

      // Notify end of request phase after ACCEPT delay
      if (mEndRequestQueue.empty()) {
        mEndRequestEvent.notify(t + ACCEPT_DELAY);
      }
      mEndRequestQueue.push(&trans);

      // AT-noTA target
      // - always return false
      // - seperate call to indicate end of phase (do not update phase or t)
      return tlm::TLM_ACCEPTED;

    } else if (phase == tlm::END_RESP) {

      // response phase ends after t
      mEndResponseEvent.notify(t);

      return tlm::TLM_COMPLETED;
    }

    // Not possible
    assert(0); exit(1);
//    return tlm::TLM_COMPLETED;  //unreachable code
  }

  void endRequest()
  {
    assert(!mEndRequestQueue.empty());
    // end request phase of oldest transaction
    phase_type phase = tlm::END_REQ;
    sc_core::sc_time t = sc_core::SC_ZERO_TIME;
    transaction_type* trans = mEndRequestQueue.front();
    assert(trans);
    mEndRequestQueue.pop();
    #if ( ! NDEBUG )
    sync_enum_type r = socket->nb_transport_bw(*trans, phase, t);
    #endif /* ! NDEBUG */
    assert(r == tlm::TLM_ACCEPTED); // FIXME: initiator should return TLM_ACCEPTED?
    assert(t == sc_core::SC_ZERO_TIME); // t must be SC_ZERO_TIME

    // Notify end of request phase for next transaction after ACCEPT delay
    if (!mEndRequestQueue.empty()) {
      mEndRequestEvent.notify(ACCEPT_DELAY);
    }

    if (mResponseQueue.empty()) {
      // Start processing transaction
      // Notify begin of response phase after RESPONSE delay
      mBeginResponseEvent.notify(RESPONSE_DELAY);
    }
    mResponseQueue.push(trans);
  }

  void beginResponse()
  {
    assert(!mResponseQueue.empty());
    // start response phase of oldest transaction
    phase_type phase = tlm::BEGIN_RESP;
    sc_core::sc_time t = sc_core::SC_ZERO_TIME;
    transaction_type* trans = mResponseQueue.front();
    assert(trans);

    // Set response data
    trans->set_response_status(tlm::TLM_OK_RESPONSE);
    if (trans->get_command() == tlm::TLM_READ_COMMAND) {
       sc_dt::uint64 address = trans->get_address();
       assert(address < 400);
      *reinterpret_cast<unsigned int*>(trans->get_data_ptr()) =
        *reinterpret_cast<unsigned int*>(&mMem[address]);
    }

    switch (socket->nb_transport_bw(*trans, phase, t)) {
    case tlm::TLM_COMPLETED:
      // response phase ends after t
      mEndResponseEvent.notify(t);
      break;

    case tlm::TLM_ACCEPTED:
    case tlm::TLM_UPDATED:
     // initiator will call nb_transport to indicate end of response phase
     break;

    default:
      assert(0); exit(1);
    };
  }

  void endResponse()
  {
    assert(!mResponseQueue.empty());
    mResponseQueue.front()->release();
    mResponseQueue.pop();

    if (!mResponseQueue.empty()) {
      // Start processing next transaction
      // Notify begin of response phase after RESPONSE delay
      mBeginResponseEvent.notify(RESPONSE_DELAY);
    }
  }

private:
  const sc_core::sc_time ACCEPT_DELAY;
  const sc_core::sc_time RESPONSE_DELAY;

private:
  unsigned char mMem[400];
  std::queue<transaction_type*> mEndRequestQueue;
  sc_core::sc_event mEndRequestEvent;
  std::queue<transaction_type*> mResponseQueue;
  sc_core::sc_event mBeginResponseEvent;
  sc_core::sc_event mEndResponseEvent;
};

#endif