Hi,
I am getting null pointer access in a fairly simple sequnce-sequencer-driver flow.
Here is what i tried.
Sequence:
class my_drive_seq extends uvm_sequence#(sop_eop_trans);
`uvm_object_utils(my_drive_seq)
function new(string name = "my_drive_seq");
super.new(name);
endfunction
task body();
sop_eop_trans pkt;
pkt = sop_eop_trans::type_id::create("packet");
start_item(pkt);
assert( pkt.randomize() with {size == 5; val ==1; });
finish_item(pkt);
endtask
endclass
Agent:
class sop_eop_agnt extends uvm_agent;
`uvm_component_utils(sop_eop_agnt)
sop_eop_drv drv;
uvm_sequencer#(sop_eop_trans) seqr;
function new(string name, uvm_component parent);
super.new(name,parent);
endfunction
function void build_phase(uvm_phase phase);
super.build_phase(phase);
drv = sop_eop_drv::type_id::create("drv",this);
seqr = uvm_sequencer#(sop_eop_trans)::type_id::create("seqr",this);
endfunction
function void connect_pahse(uvm_phase phase);
drv.seq_item_port.connect(seqr.seq_item_export);
endfunction
endclass
Driver:
class sop_eop_drv extends uvm_driver#(sop_eop_trans);
`uvm_component_utils(sop_eop_drv)
sop_eop_trans item;
virtual dut_if vif;
function new(string name, uvm_component parent);
super.new(name,parent);
endfunction
function void build_phase (uvm_phase phase);
super.build_phase(phase);
if(!uvm_config_db#(virtual dut_if)::get(this,"","vif",vif));
endfunction
task run_phase(uvm_phase phase);
sop_eop_trans item;
vif.rst = 0;
repeat(100) @(posedge vif.clk);
vif.rst = 1;
repeat(10) @(posedge vif.clk);
forever begin
@vif.drv_cb;
// seq_item_port.get_next_item(item); //NULL
seq_item_port.try_next_item(item); //NULL
@vif.drv_cb;
seq_item_port.item_done();
end
endtask
endclass
Sequence Started from Test using: seq.start(m_env.m_agnt.seqr);
VCS ERROR:
Error-[NOA] Null object access
/p/psg/eda/synopsys/vcsmx/P-2019.06-SP2-7/linux64/suse/etc/uvm/tlm1/uvm_sqr_connections.svh, 45
The object at dereference depth 1 is being used before it was
constructed/allocated.
Please make sure that the object is allocated before using it.
#0 in
\uvm_seq_item_pull_port#(my_testbench_pkg::sop_eop_trans,my_testbench_pkg::sop_eop_trans)::try_next_item
