Regarding Sequence issue related to UVM1.2

sravankumarpothu · January 6, 2020, 6:12pm

Hi All, i am Sravan Kumar.

I am verifying One Small example code for testing UVM1.1d and UVM1.2 environment, i wrote a sequence and i am randomizing the packet for 5 times and driving it to the driver.
The main problem i am facing here is when i ran the environment in UVM1.1d mode it drives 5 packets to the driver and in UVM1.2 mode driver getting only 2 packets .For the third packet the sequence is stucked at the wait_grant method and drops the objection.
Why it is happening ??
can anyone provide me the solution ASAP?

class packet_sequence extends uvm_sequence # (packet);
  
  `uvm_object_utils(packet_sequence)
  
  function new (string name = "packet_sequence");
    super.new(name);
    `uvm_info("packet_sequence",$sformatf("%m"),UVM_MEDIUM);
  endfunction
  
  task body();
    `uvm_info("TRACE",$sformatf("%m"),UVM_MEDIUM);
    `uvm_info("TRACE",$sformatf("%m 11111111111"),UVM_MEDIUM);
    if (starting_phase != null)
     begin
      starting_phase.raise_objection(this);
     end 
 
    repeat (5)
    begin
      req = packet::type_id::create("req");
     `uvm_info("TRACE",$sformatf("%m wait grant"),UVM_MEDIUM);
      wait_for_grant(10, 0);    
     `uvm_info("TRACE",$sformatf("%m get grant"),UVM_MEDIUM);
      assert(req.randomize());
      send_request(req);  
     `uvm_info("TRACE",$sformatf("%m send req"),UVM_MEDIUM);
      wait_for_item_done();  
     `uvm_info("TRACE",$sformatf("%m seq task done"),UVM_MEDIUM);
    end
    
    if (starting_phase != null)
    begin
      starting_phase.drop_objection(this);
      `uvm_info("TRACE",$sformatf("%m //TESTING//"),UVM_MEDIUM);
    end
    
  endtask
  
endclass

Result:

UVM_INFO driver.sv(43) @ 0: uvm_test_top.e.ag.drv [DRIVER] Waiting for data from sequencer
UVM_INFO packet_sequence.sv(7) @ 0: reporter@@packet_sequence [packet_sequence] $unit::\packet_sequence::new 
UVM_INFO packet_sequence.sv(11) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body 
UVM_INFO packet_sequence.sv(12) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  11111111111
UVM_INFO packet.sv(20) @ 0: reporter@@req [packet] $unit::\packet::new 
UVM_INFO packet_sequence.sv(38) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  wait grant
UVM_INFO packet_sequence.sv(40) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  get grant
UVM_INFO packet_sequence.sv(45) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  send req
UVM_INFO driver.sv(46) @ 0: uvm_test_top.e.ag.drv [DRIVER] Getting data
------------------------------
Name     Type      Size  Value
------------------------------
req      packet    -     @806 
  a      integral  8     'h1  
  b      integral  8     'h3  
  doAdd  integral  1     'h0  
------------------------------
UVM_INFO driver.sv(54) @ 0: uvm_test_top.e.ag.drv [DRIVER] Driver task done
UVM_INFO driver.sv(43) @ 0: uvm_test_top.e.ag.drv [DRIVER] Waiting for data from sequencer
UVM_INFO packet_sequence.sv(47) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  seq task done
UVM_INFO packet.sv(20) @ 0: reporter@@req [packet] $unit::\packet::new 
UVM_INFO packet_sequence.sv(38) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  wait grant
UVM_INFO packet_sequence.sv(40) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  get grant
UVM_INFO packet_sequence.sv(45) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  send req
UVM_INFO driver.sv(46) @ 0: uvm_test_top.e.ag.drv [DRIVER] Getting data
------------------------------
Name     Type      Size  Value
------------------------------
req      packet    -     @826 
  a      integral  8     'h4  
  b      integral  8     'h3  
  doAdd  integral  1     'h0  
------------------------------
UVM_INFO driver.sv(54) @ 0: uvm_test_top.e.ag.drv [DRIVER] Driver task done
UVM_INFO driver.sv(43) @ 0: uvm_test_top.e.ag.drv [DRIVER] Waiting for data from sequencer
UVM_INFO packet_sequence.sv(47) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  seq task done
UVM_INFO packet.sv(20) @ 0: reporter@@req [packet] $unit::\packet::new 
UVM_INFO packet_sequence.sv(38) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body  wait grant
UVM_INFO /apps/vcsmx/vcs/P-2019.06-1//etc/uvm-1.2/src/base/uvm_report_server.svh(894) @ 0: reporter [UVM/REPORT/SERVER] 
--- UVM Report Summary ---

** Report counts by severity
UVM_INFO :   33
UVM_WARNING :    0
UVM_ERROR :    0
UVM_FATAL :    0
** Report counts by id
[DRIVER]     7
[RNTST]     1
[TRACE]    14
[UVM/RELNOTES]     1
[UVMTOP]     1
[agent]     1
[drv]     1
[env]     1
[packet]     4
[packet_sequence]     1
[test]     1

$finish called from file "/apps/vcsmx/vcs/P-2019.06-1//etc/uvm-1.2/src/base/uvm_root.svh", line 613.
$finish at simulation time                    0

cgales · January 7, 2020, 11:24am

In reply to sravan kumar pothu:

Some comments that may help you:

Don’t raise/drop objections in a sequence. You should only raise/drop one objection in your test, encompassing all of your test sequences.
Don’t use wait_for_grant()/send_request()/wait_for_item_done(). Instead, use start_item()/finish_item(). It is simpler and easier to debug.
Don’t use assert() around a randomize call. An assert statement may be optimized away inadvertently if assertions are disabled. Instead, explicitly check the return value.

All of your transactions are completing at time 0, which indicates that you may have a driver issue.

sravankumarpothu · January 7, 2020, 1:01pm

In reply to cgales:

Hi cgales,Thank you for your response.
Already I made all these changes and tried even though it is not working in UVM1.2 and it is giving the same result as before.

Below i am sharing the code which i have modified, If any mistakes i did please let me know.


class packet_sequence extends uvm_sequence # (packet);
  
  `uvm_object_utils(packet_sequence)
  
  function new (string name = "packet_sequence");
    super.new(name);
    `uvm_info("packet_sequence",$sformatf("%m"),UVM_MEDIUM);
  endfunction
  
  task body();
    `uvm_info("TRACE",$sformatf("%m"),UVM_MEDIUM);
    `uvm_info("TRACE",$sformatf("%m 11111111111"),UVM_MEDIUM);
    if (starting_phase != null)
     begin
      starting_phase.raise_objection(this);
     end 
    
    repeat(5)
      begin
        req = packet::type_id::create("req");
        `uvm_info("TRACE",$sformatf("%m wait grant"),UVM_MEDIUM);
         start_item(req);
        `uvm_info ("SEQ", $sformatf("start_item() fn call done"), UVM_MEDIUM)
         req.randomize();    
         finish_item(req);
      end  
    if (starting_phase != null)
     begin
      starting_phase.drop_objection(this);
      `uvm_info("TRACE",$sformatf("%m 77777777777"),UVM_MEDIUM);
     end
    
  endtask
  
endclass


class test extends uvm_test;
  `uvm_component_utils(test)
  env e ;
  packet_sequence p_seq;
  uvm_sequencer #(packet)   p_seqr0;
  //uvm_factory factory;
  //uvm_coreservice_t cs = uvm_coreservice_t::get();
  
  function new(string name,uvm_component parent);
    super.new(name,parent);
    `uvm_info("test",$sformatf("%m"),UVM_MEDIUM);
  endfunction : new 
  
  function void build_phase(uvm_phase phase);
    super.build_phase(phase);
    `uvm_info("TRACE",$sformatf("%m"),UVM_MEDIUM);
    e=env::type_id::create("e",this);
    p_seqr0 = uvm_sequencer#(packet)::type_id::create ("p_seqr0", this);
  endfunction : build_phase 


  function void start_of_simulation_phase (uvm_phase phase);
    super.start_of_simulation_phase(phase);
    `uvm_info("TRACE",$sformatf("%m"),UVM_MEDIUM);
    uvm_top.print_topology();
  // factory.print();
    
  endfunction : start_of_simulation_phase
  
  virtual task run_phase(uvm_phase phase);
      p_seq=packet_sequence::type_id::create("p_seq",this);
      phase.raise_objection(this);
 	  p_seq.start(p_seqr0);
      phase.drop_objection(this);
  endtask
  
endclass

class driver extends uvm_driver # (packet);
  
  `uvm_component_utils(driver);
  
    virtual add_sub_if vif;

  
  function new(string name, uvm_component parent);
    super.new(name,parent);
    `uvm_info("drv",$sformatf("%m"),UVM_MEDIUM);
  endfunction
  
  function void build_phase (uvm_phase phase );
    super.build_phase(phase);
    uvm_config_db # (virtual add_sub_if) :: get (this, "", "add_sub_if",vif);
  endfunction
  
  task run_phase (uvm_phase phase);
    super.run_phase(phase);
    
    vif.a=0;
    vif.b=0;
    vif.doAdd=0;
    
    forever   
      begin
        //for the above line we are getting a cross module reference error . 
        `uvm_info ("DRIVER", $sformatf ("Waiting for data from sequencer"), UVM_MEDIUM);
        seq_item_port.get_next_item(req);
        
        `uvm_info ("DRIVER", $sformatf ("Getting data"), UVM_MEDIUM);
    //    @(negedge vif.clk);
        send();
       // this.print();

        req.print(); 
        //this.print();
   //     @(negedge vif.clk);
        seq_item_port.item_done();
        `uvm_info ("DRIVER", $sformatf ("Driver task done"), UVM_MEDIUM);
      end

       
  endtask
  
  task send ();
    vif.a<=req.a;
    vif.b<=req.b;
    vif.doAdd<=req.doAdd;
  endtask
  
endclass

Result:
UVM_INFO driver.sv(43) @ 0: uvm_test_top.e.ag.drv [DRIVER] Waiting for data from sequencer
UVM_INFO packet_sequence.sv(7) @ 0: reporter@@p_seq [packet_sequence] $unit::\packet_sequence::new
UVM_INFO packet_sequence.sv(11) @ 0: uvm_test_top.p_seqr0@@p_seq [TRACE] $unit::\packet_sequence::body
UVM_INFO packet_sequence.sv(12) @ 0: uvm_test_top.p_seqr0@@p_seq [TRACE] $unit::\packet_sequence::body 11111111111
UVM_INFO packet.sv(20) @ 0: reporter@@req [packet] $unit::\packet::new
UVM_INFO packet_sequence.sv(21) @ 0: uvm_test_top.p_seqr0@@p_seq [TRACE] $unit::\packet_sequence::body wait grant
UVM_INFO packet_sequence.sv(7) @ 0: reporter@@packet_sequence [packet_sequence] $unit::\packet_sequence::new
UVM_INFO packet_sequence.sv(11) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body
UVM_INFO packet_sequence.sv(12) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body 11111111111
UVM_INFO packet.sv(20) @ 0: reporter@@req [packet] $unit::\packet::new
UVM_INFO packet_sequence.sv(21) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body wait grant
UVM_INFO packet_sequence.sv(23) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [SEQ] start_item() fn call done
UVM_INFO driver.sv(46) @ 0: uvm_test_top.e.ag.drv [DRIVER] Getting data

Name Type Size Value

req packet - @829
a integral 8 'h4
b integral 8 'h2
doAdd integral 1 'h1
begin_time time 64 0
depth int 32 'd2
parent sequence (name) string 15 packet_sequence
parent sequence (full name) string 38 uvm_test_top.e.ag.seqr.packet_sequence
sequencer string 22 uvm_test_top.e.ag.seqr

UVM_INFO driver.sv(55) @ 0: uvm_test_top.e.ag.drv [DRIVER] Driver task done
UVM_INFO driver.sv(43) @ 0: uvm_test_top.e.ag.drv [DRIVER] Waiting for data from sequencer
UVM_INFO packet.sv(20) @ 0: reporter@@req [packet] $unit::\packet::new
UVM_INFO packet_sequence.sv(21) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body wait grant
UVM_INFO packet_sequence.sv(23) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [SEQ] start_item() fn call done
UVM_INFO driver.sv(46) @ 0: uvm_test_top.e.ag.drv [DRIVER] Getting data

Name Type Size Value

req packet - @846
a integral 8 'h3
b integral 8 'h1
doAdd integral 1 'h1
begin_time time 64 0
depth int 32 'd2
parent sequence (name) string 15 packet_sequence
parent sequence (full name) string 38 uvm_test_top.e.ag.seqr.packet_sequence
sequencer string 22 uvm_test_top.e.ag.seqr

UVM_INFO driver.sv(55) @ 0: uvm_test_top.e.ag.drv [DRIVER] Driver task done
UVM_INFO driver.sv(43) @ 0: uvm_test_top.e.ag.drv [DRIVER] Waiting for data from sequencer
UVM_INFO packet.sv(20) @ 0: reporter@@req [packet] $unit::\packet::new
UVM_INFO packet_sequence.sv(21) @ 0: uvm_test_top.e.ag.seqr@@packet_sequence [TRACE] $unit::\packet_sequence::body wait grant
Execution interrupted or reached maximum runtime.
Done

cgales · January 7, 2020, 1:28pm

In reply to sravan kumar pothu:

Why are you creating ‘p_seqr0’ in your test? You should be starting p_seq on your agent sequencer, not an unconnected sequencer in you test.

sravankumarpothu · January 7, 2020, 1:58pm

In reply to cgales:

Hi cgales,
I tried with sequencer which is present inside the agent and i remove that p_seq0.
Now its working fine Thanks for your help.

Thanks and regards,
Sravan Kumar

Regarding Sequence issue related to UVM1.2

Name Type Size Value

req packet - @829 a integral 8 'h4 b integral 8 'h2 doAdd integral 1 'h1 begin_time time 64 0 depth int 32 'd2 parent sequence (name) string 15 packet_sequence parent sequence (full name) string 38 uvm_test_top.e.ag.seqr.packet_sequence sequencer string 22 uvm_test_top.e.ag.seqr

Name Type Size Value

req packet - @846 a integral 8 'h3 b integral 8 'h1 doAdd integral 1 'h1 begin_time time 64 0 depth int 32 'd2 parent sequence (name) string 15 packet_sequence parent sequence (full name) string 38 uvm_test_top.e.ag.seqr.packet_sequence sequencer string 22 uvm_test_top.e.ag.seqr

req packet - @829
a integral 8 'h4
b integral 8 'h2
doAdd integral 1 'h1
begin_time time 64 0
depth int 32 'd2
parent sequence (name) string 15 packet_sequence
parent sequence (full name) string 38 uvm_test_top.e.ag.seqr.packet_sequence
sequencer string 22 uvm_test_top.e.ag.seqr

req packet - @846
a integral 8 'h3
b integral 8 'h1
doAdd integral 1 'h1
begin_time time 64 0
depth int 32 'd2
parent sequence (name) string 15 packet_sequence
parent sequence (full name) string 38 uvm_test_top.e.ag.seqr.packet_sequence
sequencer string 22 uvm_test_top.e.ag.seqr