Support back to back transactions in UVM driver

UVM
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6

In reply to AL_verif:
If you don’t want to consider the control signal in the sequence item, you can do this way. In transaction class declare data as a dynamic array & constraint the size of the array from the sequence.


//sequence 
 
task body()
  req = item::type_id::create("req");

 //for single transfer
  begin
  start_item(req);
  assert(req.randomize() with{ data.size == 1;});
  finish_item(req);
  end
  //for multiple transfersi.e.,full band width
  start_item(req);
  assert(req.randomize() with{data.size == 10/*or any other values per your requirement*/;});
  finish_item(req);
endtask
 
// Now in driver you need not to do any changes 
virtual task main_phase(uvm_phase phase);
   super.main_phase(phase);
 
   forever begin
      seq_item_port.get_next_item(req);
      drive_data(reg);
      seq_item_port.item_done();
   end
endtask : main_phase
 
 
// --------------------------------------
 
virtual protected task drive_data(item curr_item);
 
   // start transaction 
   foreach(curr_item.data[i])
   begin
   @(posedge vif.clk);
   vif.valid <= 1;
   vif.data <= curr_item.data[i];
   end
   
   // release the bus 
   @ (posedge vif.clk);
   vif.valid <= 0;
   vif.data <= $random();

 
endtask:drive_data

Regards,
Shanthi
www.maven-silicon.com