Nonblocking TLM port and Imp Port

Table of Contents

This example shows how to declare, create and connect the TLM non-blocking get ports, implementing and using the TLM non-blocking get methods. In this example blocking ports of the previous example ( TLM Get ports and imp_ports ) are replaced with the non-blocking get ports. It is preferred to refer to TLM Get ports and imp_ports example before going through this example.

TLM TesetBench Components are,

———————————————————-
Name Type
———————————————————-
uvm_test_top basic_test
env environment
comp_a component_a
trans_out uvm_nonblocking_get_imp
comp_b component_b
trans_in uvm_nonblocking_get_port
———————————————————-

Declare and Create TLM Get Port in comp_b

class component_b extends uvm_component;
  
  transaction trans;
  //Step-1. Declaring the get port
  uvm_nonblocking_get_port#(transaction) trans_in;  
  `uvm_component_utils(component_b)
  
  //--------------------------------------- 
  // Constructor
  //---------------------------------------
  function new(string name, uvm_component parent);
    super.new(name, parent);
    trans_in = new("trans_in", this); //Step-2. Creating the port
  endfunction : new
  
  //---------------------------------------
  // run_phase 
  //---------------------------------------
  virtual task run_phase(uvm_phase phase);
    phase.raise_objection(this);
    `uvm_info(get_type_name(),$sformatf(" Requesting transaction."),UVM_LOW)
    
    `uvm_info(get_type_name(),$sformatf(" Before calling port get method"),UVM_LOW)
    
    //Step-3. Calling try_get to receive the transaction
    if(trans_in.try_get(trans)) begin //{
      `uvm_info(get_type_name(),$sformatf(" recived transaction 
                                            from get method"),UVM_LOW)
      `uvm_info(get_type_name(),$sformatf(" Printing trans, \n %s",
                                            trans.sprint()),UVM_LOW)
    end //} 
    else
      `uvm_info(get_type_name(),$sformatf(" Not recived transaction 
                                            from get method"),UVM_LOW)
    
    `uvm_info(get_type_name(),$sformatf(" After  calling port get method"),UVM_LOW)
    
    phase.drop_objection(this);
  endtask : run_phase
  
endclass : component_b

try_get() method is used to receive the transaction form comp_b. try_get() methods returns ‘1’ on successful receive of transaction, otherwise ‘0’.

Declare and Create TLM Imp_port in comp_a

class component_a extends uvm_component;
  
  uvm_nonblocking_get_imp#(transaction,component_a) trans_out; //Step-1: Declare get Imp_port
  
  `uvm_component_utils(component_a)
  
  //--------------------------------------- 
  // Constructor
  //---------------------------------------
  function new(string name, uvm_component parent);
    super.new(name, parent);
    trans_out = new("trans_out", this); //Step-2. Create the port
  endfunction : new
  //---------------------------------------
  // Imp port try_get method
  //---------------------------------------
  //Step-3. try_get method to send trans to comp_b
  virtual function bit try_get(output transaction trans);
    
    `uvm_info(get_type_name(),$sformatf(" Recived transaction 
                                          imp port get request"),UVM_LOW)
    trans = transaction::type_id::create("trans", this);
    
    void'(trans.randomize());
    `uvm_info(get_type_name(),$sformatf(" tranaction randomized"),UVM_LOW)
    `uvm_info(get_type_name(),$sformatf(" Printing trans, \n %s",
                                          trans.sprint()),UVM_LOW)
    `uvm_info(get_type_name(),$sformatf(" Sendting trans packet"),UVM_LOW)
    
    return 1;
  endfunction
  
  //---------------------------------------
  // Imp port can_get method
  //---------------------------------------
  //Setp-4: can_get() method. 
  virtual function bit can_get();
  endfunction
endclass : component_a

Note:
As the port is nonblocking, methods should be implemented as function not task.

* Implementing and using of can_put is shown in the next example

Connecting TLM Port and Imp Port in env

function void connect_phase(uvm_phase phase);
  comp_b.trans_in.connect(comp_a.trans_out); //Connecting the ports
endfunction : connect_phase

Simulator Output

UVM_INFO @ 0: reporter [RNTST] Running test basic_test...
------------------------------------------------------
Name Type Size Value
------------------------------------------------------
uvm_test_top basic_test - @335 
 env environment - @348 
 comp_a component_a - @357 
 trans_out uvm_nonblocking_get_imp - @366 
 comp_b component_b - @376 
 trans_in uvm_nonblocking_get_port - @385 
------------------------------------------------------
UVM_INFO component_b.sv(26) @ 0: uvm_test_top.env.comp_b [component_b] Requesting transaction.
UVM_INFO component_b.sv(28) @ 0: uvm_test_top.env.comp_b [component_b] Before calling port get method
UVM_INFO component_a.sv(24) @ 0: uvm_test_top.env.comp_a [component_a] Recived transaction imp port get request
UVM_INFO component_a.sv(28) @ 0: uvm_test_top.env.comp_a [component_a] tranaction randomized
UVM_INFO component_a.sv(29) @ 0: uvm_test_top.env.comp_a [component_a] Printing trans, 
 ---------------------------------
Name Type Size Value
---------------------------------
trans transaction - @412 
 addr integral 4 'h3 
 wr_rd integral 1 'h1 
 wdata integral 8 'h6 
---------------------------------

UVM_INFO component_a.sv(31) @ 0: uvm_test_top.env.comp_a [component_a] Sendting trans packet
UVM_INFO component_b.sv(31) @ 0: uvm_test_top.env.comp_b [component_b] recived transaction from get method
UVM_INFO component_b.sv(32) @ 0: uvm_test_top.env.comp_b [component_b] Printing trans, 
 ---------------------------------
Name Type Size Value
---------------------------------
trans transaction - @412 
 addr integral 4 'h3 
 wr_rd integral 1 'h1 
 wdata integral 8 'h6 
---------------------------------

UVM_INFO component_b.sv(37) @ 0: uvm_test_top.env.comp_b [component_b] After calling port get method
UVM_INFO /apps/vcsmx/etc/uvm-1.2/src/base/uvm_objection.svh(1270) @ 0: reporter [TEST_DONE] 
UVM_INFO /apps/vcsmx/etc/uvm-1.2/src/base/uvm_report_server.svh(847) @ 0: reporter [UVM/REPORT/SERVER]

Click to execute on

The next example shows the implementation of the try_put() method.
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