mem_bsyn.cpp

Kluwer.Academic.Pub.Systemc.From.The.Ground.Up-此全书的范例程式。

//BEGIN: mem_bsyn.cpp (systemc)
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//See hier_chan.h for more information
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#include <systemc.h>
#include "mem_bsyn.h"

void mem_bsyn::mem_thread() {
  bool                   reading = false;
  bool                   m_rw;
  unsigned long          addr;
  // Reset errors & float the data bus
  err.write(false);
  d->write(FLOAT);
  for(;;) {
    // Wait for a load instruction (active high) at a clock edge
    while (ld->read() == false) {
      wait(ld->value_changed_event()); // wait here improves efficiency
      wait(ck->posedge_event());
    };
    addr = a->read();
    if (rw->read()) { // reading
      // Allow for back-to-back reads. Verify legal addresses
      while (ld->read() && m_base <= addr && addr < m_base+m_size) {
        wait(ck->posedge_event());
        d->write(m_mem[addr-m_base]);
        addr = a->read();
        if (ld->read() && !rw->read()) { // illegal write
          cout << "ERROR:"<<name()<<"@"<<sc_time_stamp()
               << ": Illegal write ignored immediately following read: " << addr << endl;
          err.write(true);
        }//endif
      }//endwhile
      // remove data and errors at next clock edge
      wait(ck->posedge_event());
      d->write(FLOAT);
      err.write(false);
    } else { // writing
      // Validate address and write
      if (m_base <= addr && addr < m_base+m_size) {
        m_mem[addr-m_base] = d->read().to_long();
      }//endif
      wait(ck->posedge_event());
    }//endif
  }//endforever
}//end mem_bsyn::mem_thread

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//END $Id: mem_bsyn.cpp,v 1.1 2004/02/29 04:39:35 dcblack Exp $