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//=============================================================================
///  @file memory.cpp
//
///  @brief Implement memory functionality
//
///  @details
///     This class implements the memory functionality (read, write, etc.)
///     and is used by all of the targets in the examples
//
//==============================================================================
//
//  Original Authors:
//    Jack Donovan, ESLX
//
//==============================================================================

#include "reporting.h"                      // Reporting convenience macros
#include "memory.h"                         // Header for this class

using namespace sc_core;

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

/// Constructor

memory::memory    
(
  const unsigned int ID                  // Target ID
, sc_core::sc_time   read_delay          // read delay
, sc_core::sc_time   write_delay         // write delay
, sc_dt::uint64      memory_size         // memory size (bytes)
, unsigned int       memory_width        // memory width (bytes)
)
: m_ID              (ID)                        
, m_read_delay      (read_delay)           
, m_write_delay     (write_delay)
, m_memory_size     (memory_size)
, m_memory_width    (memory_width)
, m_previous_warning(false)     
{ 
/// Allocate and initalize an array for the target's memory
  m_memory = new unsigned char[size_t(m_memory_size)];

/// clear memory
  memset(m_memory, 0, size_t(m_memory_size));              

} // end Constructor

//==============================================================================
///  @fn memory::operation
//  
///  @brief performs read and write
// 
///  @details
///    This routine implements the read and  write operations. including 
///    checking for byte_enable and streaming that are not implemented
//   
//==============================================================================
void 
memory::operation     
( tlm::tlm_generic_payload  &gp     
, sc_core::sc_time          &delay_time   ///< transaction delay 
)    
{
  /// Access the required attributes from the payload
  sc_dt::uint64    address   = gp.get_address();     // memory address
  tlm::tlm_command command   = gp.get_command();     // memory command
  unsigned char    *data     = gp.get_data_ptr();    // data pointer
  unsigned  int     length   = gp.get_data_length(); // data length
  
  std::ostringstream  msg;   
  msg.str("");
  tlm::tlm_response_status response_status = check_address(gp);
  
  if (gp.get_byte_enable_ptr())
  {
    gp.set_response_status(tlm::TLM_BYTE_ENABLE_ERROR_RESPONSE);
  }
  else if (gp.get_streaming_width() != gp.get_data_length()) 
  {
    gp.set_response_status(tlm::TLM_BURST_ERROR_RESPONSE);
  }
    
  switch (command)
  {
    default:
    {
      if (m_previous_warning == false)
      {
        msg << "Target: " << m_ID 
            << " Unsupported Command Extension";
        REPORT_INFO(filename, __FUNCTION__, msg.str());
        gp.set_response_status(tlm::TLM_COMMAND_ERROR_RESPONSE);
        delay_time = sc_core::SC_ZERO_TIME;
        m_previous_warning = true;
      }
      break;
    }
    
    /// Setup a TLM_WRITE_COMMAND Informational Message and Write the Data from
    /// the Generic Payload Data pointer to Memory
    ///
    case tlm::TLM_WRITE_COMMAND:
    {
      if (response_status == tlm::TLM_OK_RESPONSE)
        {
          for (unsigned int i = 0; i < length; i++)
          {
            m_memory[address++] = data[i];     // move the data to memory
          }
          delay_time = delay_time + m_write_delay;
          report::print(m_ID, gp, filename);
        } 
      break;     
    }

    case tlm::TLM_READ_COMMAND:
    {
      if (response_status == tlm::TLM_OK_RESPONSE)
      {
        for (unsigned int i = 0; i < length; i++)
        {
          data[i] = m_memory[address++];         // move the data to memory
        }
        delay_time = delay_time + m_read_delay;
        report::print(m_ID, gp, filename);
      }     
      break;
    }
  } // end switch

  gp.set_response_status(response_status);
  
  return;
} // end memory_operation

//==============================================================================
///  @fn memory::get_mem_ptr
//  
///  @brief Method to return pointer to memory in this object
// 
///  @details
///    This routine used during dmi example
//   
//==============================================================================
unsigned char*
memory::get_mem_ptr(void)
{
  return m_memory;
}

//==============================================================================
///  @fn memory::get_delay
//  
///  @brief Method to "pull" appropriate delay from the gp
// 
///  @details
///    This routine used during several at examples
//   
//==============================================================================
void 
memory::get_delay
( tlm::tlm_generic_payload  &gp           ///< TLM2 GP reference
, sc_core::sc_time          &delay_time   ///< time to be updated
)
{
  /// Access the required attributes from the payload
  tlm::tlm_command command   = gp.get_command();     // memory command
  
  std::ostringstream  msg;   
  msg.str("");
  
  switch (command)
  {
    default:
    {
      if (m_previous_warning == false)
      {
        msg << "Target: " << m_ID 
            << " Unsupport GP command extension";
        REPORT_WARNING(filename, __FUNCTION__, msg.str());
        m_previous_warning = true;
      }
      break;
    }
    
    /// Setup a TLM_WRITE_COMMAND Informational Message and Write the Data from
    /// the Generic Payload Data pointer to Memory
    ///
    case tlm::TLM_WRITE_COMMAND:
    {
      delay_time = delay_time + m_write_delay;
      break;     
    }

    case tlm::TLM_READ_COMMAND:
    {
      delay_time = delay_time + m_read_delay;
      break;
    }
  } // end switch  
  return; 
}

//==============================================================================
///  @fn memory::check_address
//  
///  @brief Method to check if the gp is in the address range of this memory
// 
///  @details
///    This routine used to check for errors in address space
//   
//==============================================================================
tlm::tlm_response_status
memory::check_address
( tlm::tlm_generic_payload  &gp        
)
{
  sc_dt::uint64    address   = gp.get_address();     // memory address
  unsigned  int     length   = gp.get_data_length(); // data length
  
  std::ostringstream  msg;   
  msg.str("");
  
  if ( address >= m_memory_size )
  {
    msg << "Target: " << m_ID 
        <<" address out-of-range";
    REPORT_WARNING(filename, __FUNCTION__, msg.str());
    
    return tlm::TLM_ADDRESS_ERROR_RESPONSE; // operation response
  }
  else
  {
    if ( (address + length) >= m_memory_size )   
    {
      msg << "Target: " << m_ID 
          << " address will go out of bounds";
      REPORT_WARNING(filename, __FUNCTION__, msg.str());
      
      return tlm::TLM_ADDRESS_ERROR_RESPONSE; // operation response
    }
    
  return tlm::TLM_OK_RESPONSE;
  }
} // end check address


 
