How to insert timings in an untimed model

[Khushi]

Hi

i am trying to understand how we can insert timings in an untimed model

 

any example will be a great help

 

thanks

khushi

[David Black]

Insert timing delays with sc_core::wait(sc_time) method as called out by either the specification or your best understanding of the likely RTL result.

Perhaps you have a function that compresses a JPEG image and experience shows that it take 550 to 568 clocks on an existing design. If you think you can improve the algorithm by 30% then using some statistical approach:

#include <systemc>
#include <random>
sc_core::sc_time const period { 15.0, SC_NS }; //< clock period
...

void compress_jpeg( args... ) {
  unsigned int seed = 1;
  std::default_random_engine generator { seed };
  std::uniform_distribution<int> distribution { 550, 568 };
  
  // Compress jpeg using software methods
  ...
  
  wait( 0.30 * distribution(generator) * period );
}

No magic. Accuracy is dependent on your experience and best effort WAG. You may have a more sophisticated time calculation if you think you know more.