What is the difference between ovm_transaction and ovm_sequence_item?

OVM
8

In reply to murali anumanth:

Murali,

  1. Yes, you can use ovm_transaction class object in the ovm_sequence_item class. But why do you need to do that? For an user, there is no difference between an ovm_transaction class & ovm_sequence_item class. They can be used in the same manner.
  2. There is no such hierarchy needed as you did, which is more confusing
  3. Just get rid of basic_transfer class. Whatever sequence you need to create, do that in my_sequence class by creating the wap/wdp etc objects there.
  4. My one more suggestion is to combine address-phase & data-phase into a single transaction (sequence item) so taht it will be easy for post-processing.
  5. set_transaction_id can be used only after you create that transaction. You can do the following in the my_sequence class:
virtual task body();

  wap = write_waddr_phase::type_id::create("wap");
  wdp = write_waddr_phase::type_id::create("wdp");

  start_item(wap);
  wap.set_transaction_id(1);
  assert(wap.randomize());
  finish_item(wap);

  start_item(wdp);
  wdp.set_transaction_id(1); // I hope you want to give same ID for a seq
  assert(wdp.randomize());
  finish_item(wdp);

endtask