xref: /gem5/src/systemc/tests/systemc/misc/user_guide/chpt3.1/fsmr.cpp

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/*****************************************************************************

  fsmr.cpp --

  Original Author: Martin Janssen, Synopsys, Inc., 2002-02-15

 *****************************************************************************/

/*****************************************************************************

  MODIFICATION LOG - modifiers, enter your name, affiliation, date and
  changes you are making here.

      Name, Affiliation, Date:
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/* File containing functionality of the FSM recognizer */

#include "fsmr.h"

void fsm_recognizer::entry()
{
  char c;
  int state = 0;
  bool out;

  while (true) {
    do { wait(); } while (data_ready != true);
    c = input_char.read();
    cout << c << flush;

    switch(state) {
    case 0:
      if (c == pattern[0]) state = 1;
      else state = 0;
      out = false;
      break;
    case 1:
      if (c == pattern[1]) state = 2;
      else state = 0;
      out = false;
      break;
    case 2:
      if (c == pattern[2]) state = 3;
      else state = 0;
      out = false;
      break;
    case 3:
      if (c == pattern[3]) out = true;
      else out = false;
      state = 0;
      break;
    default:
      cout << "Error: FSM in bad state." << endl;
      break;
    }

    found.write(out);
    wait(); // for writing the found signal
    found.write(false); // reset the found signal
  }
}