`include "uvm_pkg.sv"
`include "uvm_macros.svh"
import uvm_pkg::*;
class user_seq_item extends uvm_sequence_item ;
// Factory Registration N Object Constructor
endclass
typedef uvm_sequencer #(user_seq_item) user_sequencer ;
class my_driver extends uvm_driver #(user_seq_item) ;
// Factory Registration N Component Constructor
task main_phase( uvm_phase phase ) ;
`ifdef TRY
seq_item_port.try_next_item(req) ;
`else
seq_item_port.get_next_item(req) ;
`endif
seq_item_port.item_done() ;
endtask
endclass
class user_seq extends uvm_sequence#(user_seq_item) ;
// Factory Registration N Object Constructor
`ifdef PRE_DO
virtual task pre_do ( bit is_item ) ;
#50 ;
endtask
`endif
task body() ;
req = user_seq_item::type_id::create("req") ;
start_item(req);
`ifndef PRE_DO
#100 ;
`endif
finish_item(req);
`uvm_info("body",$sformatf(" Task finish_item() Unblocks "),UVM_NONE)
endtask
endclass
class user_test extends uvm_test ;
// Factory Registration N Component Constructor
my_driver drv ;
user_sequencer seqr ;
function void build_phase ( uvm_phase phase ) ;
drv = my_driver::type_id::create("drv",this) ;
seqr = user_sequencer::type_id::create("seqr",this) ;
endfunction
function void connect_phase ( uvm_phase phase ) ;
drv.seq_item_port.connect( seqr.seq_item_export ) ;
endfunction
task main_phase( uvm_phase phase ) ;
user_seq seq ;
phase.raise_objection(this);
seq = user_seq::type_id::create("seq");
seq.start(seqr);
phase.drop_objection(this);
endtask
endclass
module Top_TB ;
initial run_test("user_test") ;
endmoduleONLY when using try_next_item I observe UVM_ERROR followed by UVM_FATAL .
//===========================================================================================
// OUTPUT with +define+TRY
//===========================================================================================
//
// UVM_INFO @ 0: reporter [RNTST] Running test user_test...
// UVM_ERROR @ 0: uvm_test_top.seqr [TRY_NEXT_BLOCKED] try_next_item: the selected sequence 'uvm_test_top.seqr.seq' did not produce an item within an NBA delay. Sequences should not consume time between calls to start_item and finish_item. Returning null item.
// UVM_FATAL @ 0: uvm_test_top.seqr [uvm_test_top.seqr] Item_done() called with no outstanding requests. Each call to item_done() must be paired with a previous call to get_next_item().
//
//===========================================================================================
//===========================================================================================
// OUTPUT with +define+TRY +define+PRE_DO
//===========================================================================================
//
// UVM_INFO @ 0: reporter [RNTST] Running test user_test...
// UVM_ERROR @ 0: uvm_test_top.seqr [TRY_NEXT_BLOCKED] try_next_item: the selected sequence 'uvm_test_top.seqr.seq' did not produce an item within an NBA delay. Sequences should not consume time between calls to start_item and finish_item. Returning null item.
// UVM_FATAL @ 0: uvm_test_top.seqr [uvm_test_top.seqr] Item_done() called with no outstanding requests. Each call to item_done() must be paired with a previous call to get_next_item().
//
//===========================================================================================
[ Q ] Why is it that ONLY try_next_item gives the UVM_ERROR N UVM_FATAL whereas get_next_item works fine ?
