put() is one of the TLM method which can be used to communicate between a Producer& a Consumer.

port is the interface which calls put() method and export is the interface which provides the implementation of put() method. That way, TLM communication is independent of the Producer and Consumer abstraction level.

As shown in the figure below, a port is always symbolized with a square and export with a circle.

This communication mechanism would be more clear from the UVM code provided below:

`include “uvm_macros.svh”

module test;

import uvm_pkg::*;

/////////// Transaction /////////////////////////
class txn extends uvm_sequence_item;
`uvm_object_utils(txn)

typedef enum {READ, WRITE} kind_t;
rand bit [7:0] addr;
rand byte data;
kind_t kind;

function new (string name = “”);
super.new(name);
kind = kind'($urandom_range(0,1));
endfunction: new

endclass: txn

///////////// Producer //////////////////////////
class producer extends uvm_component;
`uvm_component_utils(producer)

uvm_blocking_put_port #(txn) my_port;

function new (string name, uvm_component parent);
super.new(name, parent);
my_port = new (“my_port”, this);
endfunction: new

task run_phase(uvm_phase phase);
for (int packet = 1; packet<11; packet++)
begin
txn t;
t = txn::type_id::create(“t”, this);
`uvm_info(“PID”, $sformatf(“Packet no. %d is sent”, packet), UVM_LOW)
my_port.put(t);
#10;
end
endtask: run_phase

endclass: producer

/////////// Consumer //////////////////////////
class consumer extends uvm_component;
`uvm_component_utils(consumer)

uvm_blocking_put_imp #(txn, consumer) my_export;

function new (string name, uvm_component parent);
super.new(name, parent);
my_export = new(“my_export”, this);
endfunction: new

task put (txn t);
case(t.kind)
t.READ: $display(“Read transaction”);
t.WRITE: $display(“Write transaction”);
endcase

endtask: put

endclass: consumer

///////////// Environment ///////////////
class env extends uvm_env;

function new (string name = “env”);
super.new(name);
endfunction: new

producer p1;
consumer c1;

function void build_phase(uvm_phase phase);
super.build_phase(phase);
p1 = producer::type_id::create(“p1”, this);
c1 = consumer::type_id::create(“c1”, this);
endfunction: build_phase

function void connect_phase(uvm_phase phase);
p1.my_port.connect(c1.my_export);
endfunction: connect_phase

task run_phase(uvm_phase phase);
phase.raise_objection(this);
#1000;
phase.drop_objection(this);
endtask: run_phase

endclass: env

env e;

initial
begin
e = new();
run_test();
end

endmodule: test