ESL Loose Timing Continued

The quantum keeper code is just a conditional resynch:

  if (delay > myQ) { sc_wait(delay); delay = 0; }

By calling sc_wait(delay) the simulation time will advance to where the caller has got to while running other pending processes. The myQuantum could be a system default value or a special value for each thread or component.

(We here write sc_wait to emphasise it is the SystemC kernel primitive systemc::wait, not the unix call.)

Or where a thread needs to spin, waiting for a result from some other thread:

  while (!condition_of_interest)
  {
    sc_wait(delay);
    delay = 0;
  }  

Generally, we can choose the quantum according to our current modelling interest:

• Large time quantum: fast simulation,
• Small time quantum: transaction order interleaving is more accurate.

Transactions may execute in a different sequence from reality: sequential consistency compromised ? Bugs exposed?